Subject: Re: [PATCH net-next-2.6 v2] can: Topcliff: PCH_CAN driver: Fix build warnings

From: Marc Kleine-Budde <[email-masked]>
Date: Mon, 01 Nov 2010 12:05:47 +0100

Hello,

On 10/29/2010 09:32 PM, Wolfgang Grandegger wrote:

some comments inline.

[...]

>>> --- /dev/null
>>> +++ b/drivers/net/can/pch_can.c
>>> @@ -0,0 +1,1436 @@
>>> +/*
>>> + * Copyright (C) 1999 - 2010 Intel Corporation.
>>> + * Copyright (C) 2010 OKI SEMICONDUCTOR CO., LTD.
>>> + *
>>> + * This program is free software; you can redistribute it and/or modify
>>> + * it under the terms of the GNU General Public License as published by
>>> + * the Free Software Foundation; version 2 of the License.
>>> + *
>>> + * This program is distributed in the hope that it will be useful,
>>> + * but WITHOUT ANY WARRANTY; without even the implied warranty of
>>> + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
>>> + * GNU General Public License for more details.
>>> + *
>>> + * You should have received a copy of the GNU General Public License
>>> + * along with this program; if not, write to the Free Software
>>> + * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307, USA.
>>> + */
>>> +
>>> +#include <linux/interrupt.h>
>>> +#include <linux/delay.h>
>>> +#include <linux/io.h>
>>> +#include <linux/module.h>
>>> +#include <linux/sched.h>
>>> +#include <linux/pci.h>
>>> +#include <linux/init.h>
>>> +#include <linux/kernel.h>
>>> +#include <linux/types.h>
>>> +#include <linux/errno.h>
>>> +#include <linux/netdevice.h>
>>> +#include <linux/skbuff.h>
>>> +#include <linux/can.h>
>>> +#include <linux/can/dev.h>
>>> +#include <linux/can/error.h>
>>> +
>>> +#define MAX_MSG_OBJ		32
>>> +#define MSG_OBJ_RX		0 /* The receive message object flag. */
>>> +#define MSG_OBJ_TX		1 /* The transmit message object flag. */
>>> +
>>> +#define CAN_CTRL_INIT		0x0001 /* The INIT bit of CANCONT register. */
>>> +#define CAN_CTRL_IE		0x0002 /* The IE bit of CAN control register */
>>> +#define CAN_CTRL_IE_SIE_EIE	0x000e
>>> +#define CAN_CTRL_CCE		0x0040
>>> +#define CAN_CTRL_OPT		0x0080 /* The OPT bit of CANCONT register. */
>>> +#define CAN_OPT_SILENT		0x0008 /* The Silent bit of CANOPT reg. */
>>> +#define CAN_OPT_LBACK		0x0010 /* The LoopBack bit of CANOPT reg. */
>>> +#define CAN_CMASK_RX_TX_SET	0x00f3
>>> +#define CAN_CMASK_RX_TX_GET	0x0073
>>> +#define CAN_CMASK_ALL		0xff
>>> +#define CAN_CMASK_RDWR		0x80
>>> +#define CAN_CMASK_ARB		0x20
>>> +#define CAN_CMASK_CTRL		0x10
>>> +#define CAN_CMASK_MASK		0x40
>>> +#define CAN_CMASK_NEWDAT	0x04
>>> +#define CAN_CMASK_CLRINTPND	0x08
>>> +
>>> +#define CAN_IF_MCONT_NEWDAT	0x8000
>>> +#define CAN_IF_MCONT_INTPND	0x2000
>>> +#define CAN_IF_MCONT_UMASK	0x1000
>>> +#define CAN_IF_MCONT_TXIE	0x0800
>>> +#define CAN_IF_MCONT_RXIE	0x0400
>>> +#define CAN_IF_MCONT_RMTEN	0x0200
>>> +#define CAN_IF_MCONT_TXRQXT	0x0100
>>> +#define CAN_IF_MCONT_EOB	0x0080
>>> +#define CAN_IF_MCONT_DLC	0x000f
>>> +#define CAN_IF_MCONT_MSGLOST	0x4000
>>> +#define CAN_MASK2_MDIR_MXTD	0xc000
>>> +#define CAN_ID2_DIR		0x2000
>>> +#define CAN_ID_MSGVAL		0x8000
>>> +
>>> +#define CAN_STATUS_INT		0x8000
>>> +#define CAN_IF_CREQ_BUSY	0x8000
>>> +#define CAN_ID2_XTD		0x4000
>>> +
>>> +#define CAN_REC			0x00007f00
>>> +#define CAN_TEC			0x000000ff
>>
>> A prefix for like PCH_ instead of CAN_ for all those define above would
>> be fine to avoid namespace clashes and/or confusion with the defines from the socketcan framework.
>>
>>> +
>>> +#define PCH_RX_OK		0x00000010
>>> +#define PCH_TX_OK		0x00000008
>>> +#define PCH_BUS_OFF		0x00000080
>>> +#define PCH_EWARN		0x00000040
>>> +#define PCH_EPASSIV		0x00000020
>>> +#define PCH_LEC0		0x00000001
>>> +#define PCH_LEC1		0x00000002
>>> +#define PCH_LEC2		0x00000004
>>
>> These are just single set bit, please use BIT()
>> Consider adding the name of the corresponding register to the define's
>> name.
>>
>>> +#define PCH_LEC_ALL		(PCH_LEC0 | PCH_LEC1 | PCH_LEC2)
>>> +#define PCH_STUF_ERR		PCH_LEC0
>>> +#define PCH_FORM_ERR		PCH_LEC1
>>> +#define PCH_ACK_ERR		(PCH_LEC0 | PCH_LEC1)
>>> +#define PCH_BIT1_ERR		PCH_LEC2
>>> +#define PCH_BIT0_ERR		(PCH_LEC0 | PCH_LEC2)
>>> +#define PCH_CRC_ERR		(PCH_LEC1 | PCH_LEC2)
> 
> This is an enumeration:
> 
> enum {
> 	PCH_STUF_ERR = 1,
> 	PCH_FORM_ERR,
> 	PCH_ACK_ERR,
> 	PCH_BIT1_ERR;
> 	PCH_BIT0_ERR,
> 	PCH_CRC_ERR,
> 	PCH_LEC_ALL;
                   ^
","

> }
   ^
";"

> 
> Also, s/PCH_/PCH_LEC_/ would be nice.

ACK

> 
>>> +/* bit position of certain controller bits. */
>>> +#define BIT_BITT_BRP		0
>>> +#define BIT_BITT_SJW		6
>>> +#define BIT_BITT_TSEG1		8
>>> +#define BIT_BITT_TSEG2		12
>>> +#define BIT_IF1_MCONT_RXIE	10
>>> +#define BIT_IF2_MCONT_TXIE	11
>>> +#define BIT_BRPE_BRPE		6
>>> +#define BIT_ES_TXERRCNT		0
>>> +#define BIT_ES_RXERRCNT		8
>>
>> these are usually called SHIFT
>>
>>> +#define MSK_BITT_BRP		0x3f
>>> +#define MSK_BITT_SJW		0xc0
>>> +#define MSK_BITT_TSEG1		0xf00
>>> +#define MSK_BITT_TSEG2		0x7000
>>> +#define MSK_BRPE_BRPE		0x3c0
>>> +#define MSK_BRPE_GET		0x0f
>>> +#define MSK_CTRL_IE_SIE_EIE	0x07
>>> +#define MSK_MCONT_TXIE		0x08
>>> +#define MSK_MCONT_RXIE		0x10
>>
>> MSK or MASK is okay, however the last two are just single bits.
>>
>> Please add a PCH_ prefix here, too.
>>
>>> +#define PCH_CAN_NO_TX_BUFF	1
>>> +#define COUNTER_LIMIT		10
>>
>> dito
>>
>>> +
>>> +#define PCH_CAN_CLK		50000000	/* 50MHz */
>>> +
>>> +/*
>>> + * Define the number of message object.
>>> + * PCH CAN communications are done via Message RAM.
>>> + * The Message RAM consists of 32 message objects.
>>> + */
>>> +#define PCH_RX_OBJ_NUM		26  /* 1~ PCH_RX_OBJ_NUM is Rx*/
>>> +#define PCH_TX_OBJ_NUM		6  /* PCH_RX_OBJ_NUM is RX ~ Tx*/
>>> +#define PCH_OBJ_NUM		(PCH_TX_OBJ_NUM + PCH_RX_OBJ_NUM)
>>
>> You define MAX_MSG_OBJ earlier, seems like two names for the same value.
>>
>>> +
>>> +#define PCH_FIFO_THRESH		16
>>> +
>>> +enum pch_can_mode {
>>> +	PCH_CAN_ENABLE,
>>> +	PCH_CAN_DISABLE,
>>> +	PCH_CAN_ALL,
>>> +	PCH_CAN_NONE,
>>> +	PCH_CAN_STOP,
>>> +	PCH_CAN_RUN,
>>> +};
>>> +
>>> +struct pch_can_regs {
>>> +	u32 cont;
>>> +	u32 stat;
>>> +	u32 errc;
>>> +	u32 bitt;
>>> +	u32 intr;
>>> +	u32 opt;
>>> +	u32 brpe;
>>> +	u32 reserve1;
>>
>> VVVV
>>> +	u32 if1_creq;
>>> +	u32 if1_cmask;
>>> +	u32 if1_mask1;
>>> +	u32 if1_mask2;
>>> +	u32 if1_id1;
>>> +	u32 if1_id2;
>>> +	u32 if1_mcont;
>>> +	u32 if1_dataa1;
>>> +	u32 if1_dataa2;
>>> +	u32 if1_datab1;
>>> +	u32 if1_datab2;
>> ^^^^
>>
>> these registers and....
>>
>>> +	u32 reserve2;
>>> +	u32 reserve3[12];
>>
>> ...and these
>>
>> VVVV
>>> +	u32 if2_creq;
>>> +	u32 if2_cmask;
>>> +	u32 if2_mask1;
>>> +	u32 if2_mask2;
>>> +	u32 if2_id1;
>>> +	u32 if2_id2;
>>> +	u32 if2_mcont;
>>> +	u32 if2_dataa1;
>>> +	u32 if2_dataa2;
>>> +	u32 if2_datab1;
>>> +	u32 if2_datab2;
>>
>> ^^^^
>>
>> ...are identical. I suggest to make a struct defining a complete
>> "Message Interface Register Set". If you include the correct number of
>> reserved bytes in the struct, you can have an array of two of these
>> structs in the struct pch_can_regs.
> 
> Yep, that would be nice. Using it consequently would also allow to
> remove duplicated code efficiently. I will name it "struct pch_can_if"
> for latter references.
> 
>>
>>> +	u32 reserve4;
>>> +	u32 reserve5[20];
>>> +	u32 treq1;
>>> +	u32 treq2;
>>> +	u32 reserve6[2];
>>> +	u32 reserve7[56];
>>> +	u32 reserve8[3];
> 
> Why not just one reserveX ?
> 
>>> +	u32 srst;
>>> +};
>>> +
>>> +struct pch_can_priv {
>>> +	struct can_priv can;
>>> +	struct pci_dev *dev;
>>> +	unsigned int tx_enable[MAX_MSG_OBJ];
>>> +	unsigned int rx_enable[MAX_MSG_OBJ];
>>> +	unsigned int rx_link[MAX_MSG_OBJ];
>>> +	unsigned int int_enables;
>>> +	unsigned int int_stat;
>>> +	struct net_device *ndev;
>>> +	spinlock_t msgif_reg_lock; /* Message Interface Registers Access Lock*/
>>                                                                             ^^^
>> please add a whitespace
>>
>>> +	unsigned int msg_obj[MAX_MSG_OBJ];
>>> +	struct pch_can_regs __iomem *regs;
>>> +	struct napi_struct napi;
>>> +	unsigned int tx_obj;	/* Point next Tx Obj index */
>>> +	unsigned int use_msi;
>>> +};
>>> +
>>> +static struct can_bittiming_const pch_can_bittiming_const = {
>>> +	.name = "pch_can",
>>> +	.tseg1_min = 1,
>>> +	.tseg1_max = 16,
>>> +	.tseg2_min = 1,
>>> +	.tseg2_max = 8,
>>> +	.sjw_max = 4,
>>> +	.brp_min = 1,
>>> +	.brp_max = 1024, /* 6bit + extended 4bit */
>>> +	.brp_inc = 1,
>>> +};
>>> +
>>> +static DEFINE_PCI_DEVICE_TABLE(pch_pci_tbl) = {
>>> +	{PCI_VENDOR_ID_INTEL, 0x8818, PCI_ANY_ID, PCI_ANY_ID,},
>>> +	{0,}
>>> +};
>>> +MODULE_DEVICE_TABLE(pci, pch_pci_tbl);
>>> +
>>> +static inline void pch_can_bit_set(u32 *addr, u32 mask)
>>                                       ^^^^^
>>
>> that should be an void __iomem *, see mail I've send the other day.
>> Please use sparse to check for this kinds of errors.
>> (Compile the driver with C=2, i.e.: make drivers/net/can/pch_can.ko C=2)
>>
>>> +{
>>> +	iowrite32(ioread32(addr) | mask, addr);
>>> +}
>>> +
>>> +static inline void pch_can_bit_clear(u32 *addr, u32 mask)
>>                                         ^^^^^
>>
>> dito
>>
>>> +{
>>> +	iowrite32(ioread32(addr) & ~mask, addr);
>>> +}
>>> +
>>> +static void pch_can_set_run_mode(struct pch_can_priv *priv,
>>> +				 enum pch_can_mode mode)
>>> +{
>>> +	switch (mode) {
>>> +	case PCH_CAN_RUN:
>>> +		pch_can_bit_clear(&priv->regs->cont, CAN_CTRL_INIT);
>>> +		break;
>>> +
>>> +	case PCH_CAN_STOP:
>>> +		pch_can_bit_set(&priv->regs->cont, CAN_CTRL_INIT);
>>> +		break;
>>> +
>>> +	default:
>>> +		dev_err(&priv->ndev->dev, "%s -> Invalid Mode.\n", __func__);
>>> +		break;
>>> +	}
>>> +}
>>> +
>>> +static void pch_can_set_optmode(struct pch_can_priv *priv)
>>> +{
>>> +	u32 reg_val = ioread32(&priv->regs->opt);
>>> +
>>> +	if (priv->can.ctrlmode & CAN_CTRLMODE_LISTENONLY)
>>> +		reg_val |= CAN_OPT_SILENT;
>>> +
>>> +	if (priv->can.ctrlmode & CAN_CTRLMODE_LOOPBACK)
>>> +		reg_val |= CAN_OPT_LBACK;
>>> +
>>> +	pch_can_bit_set(&priv->regs->cont, CAN_CTRL_OPT);
>>> +	iowrite32(reg_val, &priv->regs->opt);
>>> +}
>>> +
>>
>> IMHO the function name is missleading, if I understand the code
>> correctly, this functions triggers the transmission of the message.
>> After this it checks for busy, but 
>>
>>> +static void pch_can_check_if_busy(u32 __iomem *creq_addr, u32 num)
>>                                      ^^^^
>>
>> that should probaby be a void
> 
> With separate structs for if1 and i2, a pointer to the relevant "struct
> pch_can_if" could be passed instead.
> 
>>> +{
>>> +	u32 counter = COUNTER_LIMIT;
>>> +	u32 ifx_creq;
>>> +
>>> +	iowrite32(num, creq_addr);
>>> +	while (counter) {
>>> +		ifx_creq = ioread32(creq_addr) & CAN_IF_CREQ_BUSY;
>>> +		if (!ifx_creq)
>>> +			break;
>>> +		counter--;
>>> +		udelay(1);
>>> +	}
>>> +	if (!counter)
>>> +		pr_err("%s:IF1 BUSY Flag is set forever.\n", __func__);
>>> +}
>>> +
>>> +static void pch_can_set_int_enables(struct pch_can_priv *priv,
>>> +				    enum pch_can_mode interrupt_no)
>>> +{
>>> +	switch (interrupt_no) {
>>> +	case PCH_CAN_ENABLE:
>>> +		pch_can_bit_set(&priv->regs->cont, CAN_CTRL_IE);
>>
>> noone uses this case.
>>
>>> +		break;
>>> +
>>> +	case PCH_CAN_DISABLE:
>>> +		pch_can_bit_clear(&priv->regs->cont, CAN_CTRL_IE);
>>> +		break;
>>> +
>>> +	case PCH_CAN_ALL:
>>> +		pch_can_bit_set(&priv->regs->cont, CAN_CTRL_IE_SIE_EIE);
>>> +		break;
>>> +
>>> +	case PCH_CAN_NONE:
>>> +		pch_can_bit_clear(&priv->regs->cont, CAN_CTRL_IE_SIE_EIE);
>>> +		break;
>>> +
>>> +	default:
>>> +		dev_err(&priv->ndev->dev, "Invalid interrupt number.\n");
>>> +		break;
>>> +	}
>>> +}
>>> +
>>> +static void pch_can_set_rx_enable(struct pch_can_priv *priv, u32 buff_num,
>>> +				  int set)
>>> +{
>>> +	unsigned long flags;
>>> +
>>> +	spin_lock_irqsave(&priv->msgif_reg_lock, flags);
>>> +	/* Reading the receive buffer data from RAM to Interface1 registers */
>>> +	iowrite32(CAN_CMASK_RX_TX_GET, &priv->regs->if1_cmask);
>>> +	pch_can_check_if_busy(&priv->regs->if1_creq, buff_num);
>>> +
>>> +	/* Setting the IF1MASK1 register to access MsgVal and RxIE bits */
>>> +	iowrite32(CAN_CMASK_RDWR | CAN_CMASK_ARB | CAN_CMASK_CTRL,
>>> +		  &priv->regs->if1_cmask);
>>> +
>>> +	if (set == 1) {
>>> +		/* Setting the MsgVal and RxIE bits */
>>> +		pch_can_bit_set(&priv->regs->if1_mcont, CAN_IF_MCONT_RXIE);
>>> +		pch_can_bit_set(&priv->regs->if1_id2, CAN_ID_MSGVAL);
>>> +
>>> +	} else if (set == 0) {
>>> +		/* Resetting the MsgVal and RxIE bits */
>>> +		pch_can_bit_clear(&priv->regs->if1_mcont, CAN_IF_MCONT_RXIE);
>>> +		pch_can_bit_clear(&priv->regs->if1_id2, CAN_ID_MSGVAL);
>>> +	}
> 
> Why not just?
> 
> 	if (set)
> 	else
> 
> 
>>> +	pch_can_check_if_busy(&priv->regs->if1_creq, buff_num);
>>> +	spin_unlock_irqrestore(&priv->msgif_reg_lock, flags);
>>> +}
>>> +
>>> +static void pch_can_rx_enable_all(struct pch_can_priv *priv)
>>> +{
>>> +	int i;
>>> +
>>> +	/* Traversing to obtain the object configured as receivers. */
>>> +	for (i = 1; i <= PCH_RX_OBJ_NUM; i++)
>>> +		pch_can_set_rx_enable(priv, i, 1);
>>> +}
>>> +
>>> +static void pch_can_rx_disable_all(struct pch_can_priv *priv)
>>> +{
>>> +	int i;
>>> +
>>> +	/* Traversing to obtain the object configured as receivers. */
>>> +	for (i = 1; i <= PCH_RX_OBJ_NUM; i++)
>>> +		pch_can_set_rx_enable(priv, i, 0);
>>> +}
>>> +
>>> +static void pch_can_set_tx_enable(struct pch_can_priv *priv, u32 buff_num,
>>> +				 u32 set)
>>> +{
>>> +	unsigned long flags;
>>> +
>>> +	spin_lock_irqsave(&priv->msgif_reg_lock, flags);
>>> +	/* Reading the Msg buffer from Message RAM to Interface2 registers. */
>>> +	iowrite32(CAN_CMASK_RX_TX_GET, &priv->regs->if2_cmask);
>>> +	pch_can_check_if_busy(&priv->regs->if2_creq, buff_num);
>>> +
>>> +	/* Setting the IF2CMASK register for accessing the
>>> +		MsgVal and TxIE bits */
>>> +	iowrite32(CAN_CMASK_RDWR | CAN_CMASK_ARB | CAN_CMASK_CTRL,
>>> +		 &priv->regs->if2_cmask);
>>> +
>>> +	if (set == 1) {
>>> +		/* Setting the MsgVal and TxIE bits */
>>> +		pch_can_bit_set(&priv->regs->if2_mcont, CAN_IF_MCONT_TXIE);
>>> +		pch_can_bit_set(&priv->regs->if2_id2, CAN_ID_MSGVAL);
>>> +	} else if (set == 0) {
>>> +		/* Resetting the MsgVal and TxIE bits. */
>>> +		pch_can_bit_clear(&priv->regs->if2_mcont, CAN_IF_MCONT_TXIE);
>>> +		pch_can_bit_clear(&priv->regs->if2_id2, CAN_ID_MSGVAL);
>>> +	}
>>> +
>>> +	pch_can_check_if_busy(&priv->regs->if2_creq, buff_num);
>>> +	spin_unlock_irqrestore(&priv->msgif_reg_lock, flags);
>>> +}
> 
> That function is almost identical to pch_can_set_rx_enable. Just if2 is
> used instead of if1 and CAN_IF_MCONT_TXIE instead of CAN_IF_MCONT_RXIE.
> With separate "struct  pch_can_if" for if1 and if2, it could be handled
> by a common function.
> 
>>> +static void pch_can_tx_enable_all(struct pch_can_priv *priv)
>>> +{
>>> +	int i;
>>> +
>>> +	/* Traversing to obtain the object configured as transmit object. */
>>> +	for (i = PCH_RX_OBJ_NUM + 1; i <= PCH_OBJ_NUM; i++)
>>> +		pch_can_set_tx_enable(priv, i, 1);
>>> +}
>>> +
>>> +static void pch_can_tx_disable_all(struct pch_can_priv *priv)
>>> +{
>>> +	int i;
>>> +
>>> +	/* Traversing to obtain the object configured as transmit object. */
>>> +	for (i = PCH_RX_OBJ_NUM + 1; i <= PCH_OBJ_NUM; i++)
>>> +		pch_can_set_tx_enable(priv, i, 0);
>>> +}
> 
> I think there is no need for separate functions for enable and disable.
> Just pass "enable" 0 or 1 like you do with "set" above.
> 
>>> +static int pch_can_int_pending(struct pch_can_priv *priv)
>>           ^^^
>>
>> make it u32 as it returns a register value, or a u16 as you only use
>> the 16 lower bits.
>>
>>> +{
>>> +	return ioread32(&priv->regs->intr) & 0xffff;
>>> +}
>>> +
>>> +static void pch_can_clear_buffers(struct pch_can_priv *priv)
>>> +{
>>> +	int i; /* Msg Obj ID (1~32) */
>>> +
>>> +	for (i = 1; i <= PCH_RX_OBJ_NUM; i++) {
>>
>> IMHO the readability would be improved if you define something like
>> PCH_RX_OBJ_START and PCH_RX_OBJ_END.
>>
>>> +		iowrite32(CAN_CMASK_RX_TX_SET, &priv->regs->if1_cmask);
>>> +		iowrite32(0xffff, &priv->regs->if1_mask1);
>>> +		iowrite32(0xffff, &priv->regs->if1_mask2);
>>> +		iowrite32(0x0, &priv->regs->if1_id1);
>>> +		iowrite32(0x0, &priv->regs->if1_id2);
>>> +		iowrite32(0x0, &priv->regs->if1_mcont);
>>> +		iowrite32(0x0, &priv->regs->if1_dataa1);
>>> +		iowrite32(0x0, &priv->regs->if1_dataa2);
>>> +		iowrite32(0x0, &priv->regs->if1_datab1);
>>> +		iowrite32(0x0, &priv->regs->if1_datab2);
>>> +		iowrite32(CAN_CMASK_RDWR | CAN_CMASK_MASK |
>>> +			  CAN_CMASK_ARB | CAN_CMASK_CTRL,
>>> +			  &priv->regs->if1_cmask);
>>> +		pch_can_check_if_busy(&priv->regs->if1_creq, i);
>>> +	}
>>> +
>>> +	for (i = PCH_RX_OBJ_NUM + 1; i <= PCH_OBJ_NUM; i++) {
>>                  ^^^^^^^^^^^^^^^^^^
>> dito for TX objects
>>
>>> +		iowrite32(CAN_CMASK_RX_TX_SET, &priv->regs->if2_cmask);
>>> +		iowrite32(0xffff, &priv->regs->if2_mask1);
>>> +		iowrite32(0xffff, &priv->regs->if2_mask2);
>>> +		iowrite32(0x0, &priv->regs->if2_id1);
>>> +		iowrite32(0x0, &priv->regs->if2_id2);
>>> +		iowrite32(0x0, &priv->regs->if2_mcont);
>>> +		iowrite32(0x0, &priv->regs->if2_dataa1);
>>> +		iowrite32(0x0, &priv->regs->if2_dataa2);
>>> +		iowrite32(0x0, &priv->regs->if2_datab1);
>>> +		iowrite32(0x0, &priv->regs->if2_datab2);
>>> +		iowrite32(CAN_CMASK_RDWR | CAN_CMASK_MASK | CAN_CMASK_ARB |
>>> +			  CAN_CMASK_CTRL, &priv->regs->if2_cmask);
>>> +		pch_can_check_if_busy(&priv->regs->if2_creq, i);
> 
> This is almost the same code as above, just if2 instead of if1. With
> separate "struct  pch_can_if" for if1 and i2, it could be handled by a
> common function.
> 
>>> +	}
>>> +}
>>> +
>>> +static void pch_can_config_rx_tx_buffers(struct pch_can_priv *priv)
>>> +{
>>> +	int i;
>>> +	unsigned long flags;
>>> +
>>> +	spin_lock_irqsave(&priv->msgif_reg_lock, flags);
>>> +
>>> +	for (i = 1; i <= PCH_RX_OBJ_NUM; i++) {
>>> +		iowrite32(CAN_CMASK_RX_TX_GET, &priv->regs->if1_cmask);
>>> +		pch_can_check_if_busy(&priv->regs->if1_creq, i);
>>
>> If I understand the code correctly, the about function triggers a
>> transfer. Why do you first trigger a transfer, then set the message contents....
>>> +
>>> +		iowrite32(0x0, &priv->regs->if1_id1);
>>> +		iowrite32(0x0, &priv->regs->if1_id2);
>>> +
>>> +		pch_can_bit_set(&priv->regs->if1_mcont, CAN_IF_MCONT_UMASK);
>>
>>     Why do you set the "Use acceptance mask" bit? We want to receive
>>     all can messages.
>>
>>> +
>>> +		/* Set FIFO mode set to 0 except last Rx Obj*/
>>> +		pch_can_bit_clear(&priv->regs->if1_mcont, CAN_IF_MCONT_EOB);
>>> +		/* In case FIFO mode, Last EoB of Rx Obj must be 1 */
>>> +		if (i == (PCH_RX_OBJ_NUM - 1))
>>> +			pch_can_bit_set(&priv->regs->if1_mcont,
>>> +					CAN_IF_MCONT_EOB);
>>
>>     Make it if () { } else { }, please.
>>
>>> +
>>> +		iowrite32(0, &priv->regs->if1_mask1);
>>> +		pch_can_bit_clear(&priv->regs->if1_mask2,
>>> +				  0x1fff | CAN_MASK2_MDIR_MXTD);
>>> +
>>> +		/* Setting CMASK for writing */
>>> +		iowrite32(CAN_CMASK_RDWR | CAN_CMASK_MASK | CAN_CMASK_ARB |
>>> +			  CAN_CMASK_CTRL, &priv->regs->if1_cmask);
>>> +
>>> +		pch_can_check_if_busy(&priv->regs->if1_creq, i);
>>
>> ...and then trigger the transfer again?
>>
>>> +	}
>>> +
>>> +	for (i = PCH_RX_OBJ_NUM + 1; i <= PCH_OBJ_NUM; i++) {
>>> +		iowrite32(CAN_CMASK_RX_TX_GET, &priv->regs->if2_cmask);
>>> +		pch_can_check_if_busy(&priv->regs->if2_creq, i);
>>
>> same question about triggering the transfer 2 times applied here, too
>>> +
>>> +		/* Resetting DIR bit for reception */
>>> +		iowrite32(0x0, &priv->regs->if2_id1);
>>> +		iowrite32(0x0, &priv->regs->if2_id2);
>>> +		pch_can_bit_set(&priv->regs->if2_id2, CAN_ID2_DIR);
>>
>> Can you combine the two accesses to >if2_id2 into one?
>>
>>> +
>>> +		/* Setting EOB bit for transmitter */
>>> +		iowrite32(CAN_IF_MCONT_EOB, &priv->regs->if2_mcont);
>>> +
>>> +		pch_can_bit_set(&priv->regs->if2_mcont,
>>> +				CAN_IF_MCONT_UMASK);
>>
>> dito for if2_mcont
>>
>>> +
>>> +		iowrite32(0, &priv->regs->if2_mask1);
>>> +		pch_can_bit_clear(&priv->regs->if2_mask2, 0x1fff);
>>> +
>>> +		/* Setting CMASK for writing */
>>> +		iowrite32(CAN_CMASK_RDWR | CAN_CMASK_MASK | CAN_CMASK_ARB |
>>> +			  CAN_CMASK_CTRL, &priv->regs->if2_cmask);
>>> +
>>> +		pch_can_check_if_busy(&priv->regs->if2_creq, i);
>>> +	}
>>> +
>>> +	spin_unlock_irqrestore(&priv->msgif_reg_lock, flags);
>>> +}
>>> +
>>> +static void pch_can_init(struct pch_can_priv *priv)
>>> +{
>>> +	/* Stopping the Can device. */
>>> +	pch_can_set_run_mode(priv, PCH_CAN_STOP);
>>> +
>>> +	/* Clearing all the message object buffers. */
>>> +	pch_can_clear_buffers(priv);
>>> +
>>> +	/* Configuring the respective message object as either rx/tx object. */
>>> +	pch_can_config_rx_tx_buffers(priv);
>>> +
>>> +	/* Enabling the interrupts. */
>>> +	pch_can_set_int_enables(priv, PCH_CAN_ALL);
>>> +}
>>> +
>>> +static void pch_can_release(struct pch_can_priv *priv)
>>> +{
>>> +	/* Stooping the CAN device. */
>>> +	pch_can_set_run_mode(priv, PCH_CAN_STOP);
>>> +
>>> +	/* Disabling the interrupts. */
>>> +	pch_can_set_int_enables(priv, PCH_CAN_NONE);
>>> +
>>> +	/* Disabling all the receive object. */
>>> +	pch_can_rx_disable_all(priv);
>>> +
>>> +	/* Disabling all the transmit object. */
>>> +	pch_can_tx_disable_all(priv);
>>> +}
>>> +
>>> +/* This function clears interrupt(s) from the CAN device. */
>>> +static void pch_can_int_clr(struct pch_can_priv *priv, u32 mask)
>>> +{
>>> +	if (mask == CAN_STATUS_INT) {
>>
>> is this a valid case?
>>
>>> +		ioread32(&priv->regs->stat);
>>> +		return;
>>> +	}
>>> +
>>> +	/* Clear interrupt for transmit object */
>>> +	if ((mask >= 1) && (mask <= PCH_RX_OBJ_NUM)) {
>>> +		/* Setting CMASK for clearing the reception interrupts. */
>>> +		iowrite32(CAN_CMASK_RDWR | CAN_CMASK_CTRL | CAN_CMASK_ARB,
>>> +			  &priv->regs->if1_cmask);
>>> +
>>> +		/* Clearing the Dir bit. */
>>> +		pch_can_bit_clear(&priv->regs->if1_id2, CAN_ID2_DIR);
>>> +
>>> +		/* Clearing NewDat & IntPnd */
>>> +		pch_can_bit_clear(&priv->regs->if1_mcont,
>>> +				  CAN_IF_MCONT_NEWDAT | CAN_IF_MCONT_INTPND);
>>> +
>>> +		pch_can_check_if_busy(&priv->regs->if1_creq, mask);
>>> +	} else if ((mask > PCH_RX_OBJ_NUM) && (mask <= PCH_OBJ_NUM)) {
>>> +		/* Setting CMASK for clearing interrupts for
>>> +		   frame transmission. */
>>
>> /*
>>  * this is the prefered style of multi line comments,
>>  * please adjust you comments
>>  */
>>
>>> +		iowrite32(CAN_CMASK_RDWR | CAN_CMASK_CTRL | CAN_CMASK_ARB,
>>> +			  &priv->regs->if2_cmask);
>>> +
>>> +		/* Resetting the ID registers. */
>>> +		pch_can_bit_set(&priv->regs->if2_id2,
>>> +			       CAN_ID2_DIR | (0x7ff << 2));
>>> +		iowrite32(0x0, &priv->regs->if2_id1);
>>> +
>>> +		/* Claring NewDat, TxRqst & IntPnd */
>>> +		pch_can_bit_clear(&priv->regs->if2_mcont,
>>> +				  CAN_IF_MCONT_NEWDAT | CAN_IF_MCONT_INTPND |
>>> +				  CAN_IF_MCONT_TXRQXT);
>>> +		pch_can_check_if_busy(&priv->regs->if2_creq, mask);
>>> +	}
>>> +}
>>> +
>>> +static u32 pch_can_get_buffer_status(struct pch_can_priv *priv)
>>> +{
>>> +	return (ioread32(&priv->regs->treq1) & 0xffff) |
>>> +	       ((ioread32(&priv->regs->treq2) & 0xffff) << 16);
>>
>> the second 0xffff is not needed, as the return value is u32 and you shift by 16.
>>
>>> +}
>>> +
>>> +static void pch_can_reset(struct pch_can_priv *priv)
>>> +{
>>> +	/* write to sw reset register */
>>> +	iowrite32(1, &priv->regs->srst);
>>> +	iowrite32(0, &priv->regs->srst);
>>> +}
>>> +
>>> +static void pch_can_error(struct net_device *ndev, u32 status)
>>> +{
>>> +	struct sk_buff *skb;
>>> +	struct pch_can_priv *priv = netdev_priv(ndev);
>>> +	struct can_frame *cf;
>>> +	u32 errc;
>>> +	struct net_device_stats *stats = &(priv->ndev->stats);
>>> +	enum can_state state = priv->can.state;
>>> +
>>> +	skb = alloc_can_err_skb(ndev, &cf);
>>> +	if (!skb)
>>> +		return;
>>> +
>>> +	if (status & PCH_BUS_OFF) {
>>> +		pch_can_tx_disable_all(priv);
>>> +		pch_can_rx_disable_all(priv);
>>> +		state = CAN_STATE_BUS_OFF;
>>> +		cf->can_id |= CAN_ERR_BUSOFF;
>>> +		can_bus_off(ndev);
>>> +	}
>>> +
>>> +	/* Warning interrupt. */
>>> +	if (status & PCH_EWARN) {
>>> +		state = CAN_STATE_ERROR_WARNING;
>>> +		priv->can.can_stats.error_warning++;
>>> +		cf->can_id |= CAN_ERR_CRTL;
>>> +		errc = ioread32(&priv->regs->errc);
>>> +		if (((errc & CAN_REC) >> 8) > 96)
>>> +			cf->data[1] |= CAN_ERR_CRTL_RX_WARNING;
>>> +		if ((errc & CAN_TEC) > 96)
>>> +			cf->data[1] |= CAN_ERR_CRTL_TX_WARNING;
>>> +		dev_warn(&ndev->dev,
>>> +			"%s -> Error Counter is more than 96.\n", __func__);
>>
>> Please use just "debug" level not warning here. Consider to use
>> netdev_dbg() instead. IMHO the __func__ can be dropped and the
>> "official" name for the error is "Error Warning".
>>
>>> +	}
>>> +	/* Error passive interrupt. */
>>> +	if (status & PCH_EPASSIV) {
>>> +		priv->can.can_stats.error_passive++;
>>> +		state = CAN_STATE_ERROR_PASSIVE;
>>> +		cf->can_id |= CAN_ERR_CRTL;
>>> +		errc = ioread32(&priv->regs->errc);
>>> +		if (((errc & CAN_REC) >> 8) > 127)
>>> +			cf->data[1] |= CAN_ERR_CRTL_RX_PASSIVE;
>>> +		if ((errc & CAN_TEC) > 127)
>>> +			cf->data[1] |= CAN_ERR_CRTL_TX_PASSIVE;
>>> +		dev_err(&ndev->dev,
>>> +			"%s -> CAN controller is ERROR PASSIVE .\n", __func__);
>>
>> dito
>>
>>> +	}
>>> +
>>> +	if (status & PCH_LEC_ALL) {
>>> +		priv->can.can_stats.bus_error++;
>>> +		stats->rx_errors++;
>>> +		switch (status & PCH_LEC_ALL) {
>>
>> I suggest to convert to a if-bit-set because there might be more than
>> one bit set.
> 
> Marc, what do you mean here. It's an enumeraton. Maybe the following
> code is more clear:

Oh, I haven't looked this one up in the datasheet.
> 
> 	lec = status & PCH_LEC_ALL;
> 	if (lec > 0) {

or "if (lec)", YMMV

> 		switch (lec) {
> 
>>> +		case PCH_STUF_ERR:
>>> +			cf->data[2] |= CAN_ERR_PROT_STUFF;
>>> +			break;
>>> +		case PCH_FORM_ERR:
>>> +			cf->data[2] |= CAN_ERR_PROT_FORM;
>>> +			break;
>>> +		case PCH_ACK_ERR:
>>> +			cf->data[2] |= CAN_ERR_PROT_LOC_ACK |
>>> +				       CAN_ERR_PROT_LOC_ACK_DEL;
> 
> Could you check what that type of bus error that is? Usually it's a ack
> lost error.
> 
>>> +			break;
>>> +		case PCH_BIT1_ERR:
>>> +		case PCH_BIT0_ERR:
>>> +			cf->data[2] |= CAN_ERR_PROT_BIT;
>>> +			break;
>>> +		case PCH_CRC_ERR:
>>> +			cf->data[2] |= CAN_ERR_PROT_LOC_CRC_SEQ |
>>> +				       CAN_ERR_PROT_LOC_CRC_DEL;
>>> +			break;
>>> +		default:
>>> +			iowrite32(status | PCH_LEC_ALL, &priv->regs->stat);
>>> +			break;
>>> +		}
>>> +
>>> +	}
> 
> Also, could you please add the TEC and REC:
> 
> 	cf->data[6] = ioread32(&priv->regs->errc) & CAN_TEC;
> 	cf->data[7] = (ioread32(&priv->regs->errc) & CAN_REC) >> 8;
> 
>>> +	priv->can.state = state;
>>> +	netif_receive_skb(skb);
>>> +
>>> +	stats->rx_packets++;
>>> +	stats->rx_bytes += cf->can_dlc;
>>> +}
>>> +
>>> +static irqreturn_t pch_can_interrupt(int irq, void *dev_id)
>>> +{
>>> +	struct net_device *ndev = (struct net_device *)dev_id;
>>> +	struct pch_can_priv *priv = netdev_priv(ndev);
>>> +
>>> +	pch_can_set_int_enables(priv, PCH_CAN_NONE);
>>> +	napi_schedule(&priv->napi);
>>> +
>>> +	return IRQ_HANDLED;
>>> +}
>>> +
>>> +static void pch_fifo_thresh(struct pch_can_priv *priv, int obj_id)
>>> +{
>>> +	if (obj_id < PCH_FIFO_THRESH) {
>>> +		iowrite32(CAN_CMASK_RDWR | CAN_CMASK_CTRL |
>>> +			  CAN_CMASK_ARB, &priv->regs->if1_cmask);
>>> +
>>> +		/* Clearing the Dir bit. */
>>> +		pch_can_bit_clear(&priv->regs->if1_id2, CAN_ID2_DIR);
>>> +
>>> +		/* Clearing NewDat & IntPnd */
>>> +		pch_can_bit_clear(&priv->regs->if1_mcont,
>>> +				  CAN_IF_MCONT_INTPND);
>>> +		pch_can_check_if_busy(&priv->regs->if1_creq, obj_id);
>>> +	} else if (obj_id > PCH_FIFO_THRESH) {
>>> +		pch_can_int_clr(priv, obj_id);
>>> +	} else if (obj_id == PCH_FIFO_THRESH) {
>>> +		int cnt;
>>> +		for (cnt = 0; cnt < PCH_FIFO_THRESH; cnt++)
>>> +			pch_can_int_clr(priv, cnt+1);
>>> +	}
>>> +}
>>> +
>>> +static int pch_can_rx_msg_lost(struct net_device *ndev, int obj_id)
>>> +{
>>> +	struct pch_can_priv *priv = netdev_priv(ndev);
>>> +	struct net_device_stats *stats = &(priv->ndev->stats);
>>> +	struct sk_buff *skb;
>>> +	struct can_frame *cf;
>>> +
>>> +	dev_err(&priv->ndev->dev, "Msg Obj is overwritten.\n");
> 
> Please use dev_dbg or even remove the line above.
> 
>>> +	pch_can_bit_clear(&priv->regs->if1_mcont,
>>> +			  CAN_IF_MCONT_MSGLOST);
>>> +	iowrite32(CAN_CMASK_RDWR | CAN_CMASK_CTRL,
>>> +		  &priv->regs->if1_cmask);
>>> +	pch_can_check_if_busy(&priv->regs->if1_creq, obj_id);
> 
> I think the if busy checks could be improved. Why do you need to wait here?

If I understand the code and datasheet correctly, this function doesn't
only check for busy. The functions sends the message to the object and
waits until it's finished. I suggest to split this functionality into
two functions and give them proper names. In the TX path you usually
don't need the send-message-and-wait-for-completion. In TX you need a
can-I-modify-the-mailbox-registers function and a now-send-the-mailbox
function.

The RX path needs first the waiting-for-free function, then the send and
then again the waiting-for-completion function. But as RX and TX use
always different interfaces the first waiting function can be removed.

> 
>>> +
>>> +	skb = alloc_can_err_skb(ndev, &cf);
>>> +	if (!skb)
>>> +		return -ENOMEM;
>>> +
>>> +	priv->can.can_stats.error_passive++;
>>> +	priv->can.state = CAN_STATE_ERROR_PASSIVE;
> 
> Please remove the above two bogus lines.
> 
>>> +	cf->can_id |= CAN_ERR_CRTL;
>>> +	cf->data[1] = CAN_ERR_CRTL_RX_OVERFLOW;
>>> +	stats->rx_over_errors++;
>>> +	stats->rx_errors++;
>>> +
>>> +	netif_receive_skb(skb);
>>> +
>>> +	return 0;
>>> +}
>>> +
>>> +static int pch_can_rx_normal(struct net_device *ndev, u32 obj_num, int quota)
>>> +{
>>> +	u32 reg;
>>> +	canid_t id;
>>> +	u32 ide;
>>> +	u32 rtr;
>>> +	int rcv_pkts = 0;
>>> +	int rtn;
>>> +	int next_flag = 0;
>>> +	struct sk_buff *skb;
>>> +	struct can_frame *cf;
>>> +	struct pch_can_priv *priv = netdev_priv(ndev);
>>> +	struct net_device_stats *stats = &(priv->ndev->stats);
>>> +
>>> +	/* Reading the messsage object from the Message RAM */
>>> +	iowrite32(CAN_CMASK_RX_TX_GET, &priv->regs->if1_cmask);
>>> +	pch_can_check_if_busy(&priv->regs->if1_creq, obj_num);
>>> +
>>> +	/* Reading the MCONT register. */
>>> +	reg = ioread32(&priv->regs->if1_mcont);
>>> +	reg &= 0xffff;
>>> +
>>> +	for (; (!(reg & CAN_IF_MCONT_EOB)) && (quota > 0);
>>> +						obj_num++, next_flag = 0) {
>>> +		/* If MsgLost bit set. */
>>> +		if (reg & CAN_IF_MCONT_MSGLOST) {
>>> +			rtn = pch_can_rx_msg_lost(ndev, obj_num);
>>> +			if (!rtn)
>>> +				return rtn;
>>> +			rcv_pkts++;
>>> +			quota--;
>>> +			next_flag = 1;
>>> +		} else if (!(reg & CAN_IF_MCONT_NEWDAT))
>>> +			next_flag = 1;
>>> +
>>
>> after rearanging the code (see below..) you should be able to use a continue here.
>>
>>> +		if (!next_flag) {
>>> +			skb = alloc_can_skb(priv->ndev, &cf);
>>> +			if (!skb)
>>> +				return -ENOMEM;
>>> +
>>> +			/* Get Received data */
>>> +			ide = ((ioread32(&priv->regs->if1_id2)) & CAN_ID2_XTD);
>>> +			if (ide) {
>>> +				id = (ioread32(&priv->regs->if1_id1) & 0xffff);
>>> +				id |= (((ioread32(&priv->regs->if1_id2)) &
>>> +						    0x1fff) << 16);
>>> +				cf->can_id = (id & CAN_EFF_MASK) | CAN_EFF_FLAG;
>>                                               ^^^^^^^^^^^^^^^^^
>>
>> is the mask needed, you mask the if1_id{1,2} already
>>
>>> +			} else {
>>> +				id = (((ioread32(&priv->regs->if1_id2)) &
>>> +						  (CAN_SFF_MASK << 2)) >> 2);
>>> +				cf->can_id = (id & CAN_SFF_MASK);
>>
>> one mask can go away
>>
>>> +			}
>>> +
>>> +			rtr = ioread32(&priv->regs->if1_id2) &  CAN_ID2_DIR;
>>                                                               ^^
>>
>> remove one space
>>
>>> +
>>> +			if (rtr)
>>> +				cf->can_id |= CAN_RTR_FLAG;
>>> +
>>> +			cf->can_dlc = get_can_dlc((ioread32(&priv->regs->
>>> +						   if1_mcont)) & 0xF);
>>> +			*(u16 *)(cf->data + 0) = ioread16(&priv->regs->
>>> +							  if1_dataa1);
>>> +			*(u16 *)(cf->data + 2) = ioread16(&priv->regs->
>>> +							  if1_dataa2);
>>> +			*(u16 *)(cf->data + 4) = ioread16(&priv->regs->
>>> +							  if1_datab1);
>>> +			*(u16 *)(cf->data + 6) = ioread16(&priv->regs->
>>> +							  if1_datab2);
>>
>> are you sure, the bytes in the can package a in the correct order.
>> Please test your pch_can against a non pch_can system.
>>
>>> +
>>> +			netif_receive_skb(skb);
>>> +			rcv_pkts++;
>>> +			stats->rx_packets++;
>>> +			quota--;
>>> +			stats->rx_bytes += cf->can_dlc;
>>> +
>>> +			pch_fifo_thresh(priv, obj_num);
>>> +		}
>>> +
>>> +		/* Reading the messsage object from the Message RAM */
>>> +		iowrite32(CAN_CMASK_RX_TX_GET, &priv->regs->if1_cmask);
>>> +		pch_can_check_if_busy(&priv->regs->if1_creq, obj_num + 1);
>>> +		reg = ioread32(&priv->regs->if1_mcont);
>>
>> this is almost the same code as before the the loop, can you rearange
>> the code to avoid duplication?
>>  
>>> +	}
>>> +
>>> +	return rcv_pkts;
>>> +}
>>> +
>>> +static void pch_can_tx_complete(struct net_device *ndev, u32 int_stat)
>>> +{
>>> +	struct pch_can_priv *priv = netdev_priv(ndev);
>>> +	struct net_device_stats *stats = &(priv->ndev->stats);
>>> +	unsigned long flags;
>>> +	u32 dlc;
>>> +
>>> +	can_get_echo_skb(ndev, int_stat - PCH_RX_OBJ_NUM - 1);
>>> +	spin_lock_irqsave(&priv->msgif_reg_lock, flags);
>>> +	iowrite32(CAN_CMASK_RX_TX_GET | CAN_CMASK_CLRINTPND,
>>> +		  &priv->regs->if2_cmask);
>>> +	dlc = ioread32(&priv->regs->if2_mcont) & CAN_IF_MCONT_DLC;
>>> +	pch_can_check_if_busy(&priv->regs->if2_creq, int_stat);
>>> +	spin_unlock_irqrestore(&priv->msgif_reg_lock, flags);
>>> +	if (dlc > 8)
>>> +		dlc = 8;
>>
>> use get_can_dlc
>>
>>> +	stats->tx_bytes += dlc;
>>> +	stats->tx_packets++;
>>> +}
>>> +
>>> +static int pch_can_rx_poll(struct napi_struct *napi, int quota)
>>> +{
>>> +	struct net_device *ndev = napi->dev;
>>> +	struct pch_can_priv *priv = netdev_priv(ndev);
>>> +	u32 int_stat;
>>> +	int rcv_pkts = 0;
>>> +	u32 reg_stat;
>>> +	unsigned long flags;
>>> +
>>> +	int_stat = pch_can_int_pending(priv);
>>> +	if (!int_stat)
>>> +		goto END;
> 
> Labels should be lowercase as well.
> 
>>> +
>>> +	if ((int_stat == CAN_STATUS_INT) && (quota > 0)) {
>>> +		reg_stat = ioread32(&priv->regs->stat);
>>> +		if (reg_stat & (PCH_BUS_OFF | PCH_LEC_ALL)) {
>>> +			if ((reg_stat & PCH_LEC_ALL) != PCH_LEC_ALL) {
>>> +				pch_can_error(ndev, reg_stat);
>>> +				quota--;
>>> +			}
>>> +		}
>>> +
>>> +		if (reg_stat & PCH_TX_OK) {
>>> +			spin_lock_irqsave(&priv->msgif_reg_lock, flags);
>>> +			iowrite32(CAN_CMASK_RX_TX_GET, &priv->regs->if2_cmask);
>>> +			pch_can_check_if_busy(&priv->regs->if2_creq,
>>> +					       ioread32(&priv->regs->intr));
>>                                                ^^^^^^^^^^^^^^^^^^^^^^^^^^^
>>
>> Isn't this "int_stat". Might it be possilbe that regs->intr changes
>> between the pch_can_int_pending and here?
>>
>> What should this transfer do?
>>
>>> +			spin_unlock_irqrestore(&priv->msgif_reg_lock, flags);
>>> +			pch_can_bit_clear(&priv->regs->stat, PCH_TX_OK);
>>> +		}
>>> +
>>> +		if (reg_stat & PCH_RX_OK)
>>> +			pch_can_bit_clear(&priv->regs->stat, PCH_RX_OK);
>>> +
>>> +		int_stat = pch_can_int_pending(priv);
>>> +	}
>>> +
>>> +	if (quota == 0)
>>> +		goto END;
>>> +
>>> +	if ((int_stat >= 1) && (int_stat <= PCH_RX_OBJ_NUM)) {
>>> +		spin_lock_irqsave(&priv->msgif_reg_lock, flags);
>>> +		rcv_pkts += pch_can_rx_normal(ndev, int_stat, quota);
>>> +		spin_unlock_irqrestore(&priv->msgif_reg_lock, flags);
>>> +		quota -= rcv_pkts;
>>> +		if (rcv_pkts < 0)
>>
>> how can this happen?
>>
>>> +			goto END;
>>> +	} else if ((int_stat > PCH_RX_OBJ_NUM) && (int_stat <= PCH_OBJ_NUM)) {
>>> +		/* Handle transmission interrupt */
>>> +		pch_can_tx_complete(ndev, int_stat);
>>> +	}
>>> +
>>> +END:
>>> +	napi_complete(napi);
>>> +	pch_can_set_int_enables(priv, PCH_CAN_ALL);
>>> +
>>> +	return rcv_pkts;
>>> +}
>>> +
>>> +static int pch_set_bittiming(struct net_device *ndev)
>>> +{
>>> +	struct pch_can_priv *priv = netdev_priv(ndev);
>>> +	const struct can_bittiming *bt = &priv->can.bittiming;
>>> +	u32 canbit;
>>> +	u32 bepe;
>>> +
>>> +	/* Setting the CCE bit for accessing the Can Timing register. */
>>> +	pch_can_bit_set(&priv->regs->cont, CAN_CTRL_CCE);
>>> +
>>> +	canbit = (bt->brp - 1) & MSK_BITT_BRP;
>>> +	canbit |= (bt->sjw - 1) << BIT_BITT_SJW;
>>> +	canbit |= (bt->phase_seg1 + bt->prop_seg - 1) << BIT_BITT_TSEG1;
>>> +	canbit |= (bt->phase_seg2 - 1) << BIT_BITT_TSEG2;
>>> +	bepe = ((bt->brp - 1) & MSK_BRPE_BRPE) >> BIT_BRPE_BRPE;
>>> +	iowrite32(canbit, &priv->regs->bitt);
>>> +	iowrite32(bepe, &priv->regs->brpe);
>>> +	pch_can_bit_clear(&priv->regs->cont, CAN_CTRL_CCE);
>>> +
>>> +	return 0;
>>> +}
>>> +
>>> +static void pch_can_start(struct net_device *ndev)
>>> +{
>>> +	struct pch_can_priv *priv = netdev_priv(ndev);
>>> +
>>> +	if (priv->can.state != CAN_STATE_STOPPED)
>>> +		pch_can_reset(priv);
>>> +
>>> +	pch_set_bittiming(ndev);
>>> +	pch_can_set_optmode(priv);
>>> +
>>> +	pch_can_tx_enable_all(priv);
>>> +	pch_can_rx_enable_all(priv);
>>> +
>>> +	/* Setting the CAN to run mode. */
>>> +	pch_can_set_run_mode(priv, PCH_CAN_RUN);
>>> +
>>> +	priv->can.state = CAN_STATE_ERROR_ACTIVE;
>>> +
>>> +	return;
>>> +}
>>> +
>>> +static int pch_can_do_set_mode(struct net_device *ndev, enum can_mode mode)
>>> +{
>>> +	int ret = 0;
>>> +
>>> +	switch (mode) {
>>> +	case CAN_MODE_START:
>>> +		pch_can_start(ndev);
>>> +		netif_wake_queue(ndev);
>>> +		break;
>>> +	default:
>>> +		ret = -EOPNOTSUPP;
>>> +		break;
>>> +	}
>>> +
>>> +	return ret;
>>> +}
>>> +
>>> +static int pch_can_open(struct net_device *ndev)
>>> +{
>>> +	struct pch_can_priv *priv = netdev_priv(ndev);
>>> +	int retval;
>>> +
>>> +	/* Regsitering the interrupt. */
> 
> Typo!
> 
>>> +	retval = request_irq(priv->dev->irq, pch_can_interrupt, IRQF_SHARED,
>>> +			     ndev->name, ndev);
>>> +	if (retval) {
>>> +		dev_err(&ndev->dev, "request_irq failed.\n");
>>> +		goto req_irq_err;
>>> +	}
>>> +
>>> +	/* Open common can device */
>>> +	retval = open_candev(ndev);
>>> +	if (retval) {
>>> +		dev_err(ndev->dev.parent, "open_candev() failed %d\n", retval);
>>> +		goto err_open_candev;
>>> +	}
>>> +
>>> +	pch_can_init(priv);
>>> +	pch_can_start(ndev);
>>> +	napi_enable(&priv->napi);
>>> +	netif_start_queue(ndev);
>>> +
>>> +	return 0;
>>> +
>>> +err_open_candev:
>>> +	free_irq(priv->dev->irq, ndev);
>>> +req_irq_err:
>>> +	pch_can_release(priv);
>>> +
>>> +	return retval;
>>> +}
>>> +
>>> +static int pch_close(struct net_device *ndev)
>>> +{
>>> +	struct pch_can_priv *priv = netdev_priv(ndev);
>>> +
>>> +	netif_stop_queue(ndev);
>>> +	napi_disable(&priv->napi);
>>> +	pch_can_release(priv);
>>> +	free_irq(priv->dev->irq, ndev);
>>> +	close_candev(ndev);
>>> +	priv->can.state = CAN_STATE_STOPPED;
>>> +	return 0;
>>> +}
>>> +
>>> +static netdev_tx_t pch_xmit(struct sk_buff *skb, struct net_device *ndev)
>>> +{
>>> +	unsigned long flags;
>>> +	struct pch_can_priv *priv = netdev_priv(ndev);
>>> +	struct can_frame *cf = (struct can_frame *)skb->data;
>>> +	int tx_buffer_avail = 0;
>>
>> What I'm totally missing is the TX flow controll. Your driver has to
>> ensure that the package leave the controller in the order that come
>> into the xmit function. Further you have to stop your xmit queue if
>> you're out of tx objects and reenable if you have a object free.
>>
>> Use netif_stop_queue() and netif_wake_queue() for this.
>>
>>> +
>>> +	if (can_dropped_invalid_skb(ndev, skb))
>>> +		return NETDEV_TX_OK;
>>> +
>>> +	if (priv->tx_obj == (PCH_OBJ_NUM + 1)) { /* Point tail Obj + 1 */
>>> +		while (ioread32(&priv->regs->treq2) & 0xfc00)
>>> +			udelay(1);
>>
>> please no (possible) infinite delays!
>>
>>> +		priv->tx_obj = PCH_RX_OBJ_NUM + 1; /* Point head of Tx Obj ID */
>>> +	}
>>
>>> +
>>> +	tx_buffer_avail = priv->tx_obj;
>>
>> why has the "object" become a "buffer" now? :)
>>
>>> +	priv->tx_obj++;
>>> +
>>> +	/* Attaining the lock. */
>>> +	spin_lock_irqsave(&priv->msgif_reg_lock, flags);
>>> +
>>> +	/* Setting the CMASK register to set value*/
>>                                                  ^^^
>>
>> pleas add a whitespace
>>
>>> +	iowrite32(CAN_CMASK_RX_TX_SET, &priv->regs->if2_cmask);
>>> +
>>> +	/* If ID extended is set. */
>>> +	if (cf->can_id & CAN_EFF_FLAG) {
>>> +		iowrite32(cf->can_id & 0xffff, &priv->regs->if2_id1);
>>> +		iowrite32(((cf->can_id >> 16) & 0x1fff) | CAN_ID2_XTD,
>>> +			    &priv->regs->if2_id2);
>>> +	} else {
>>> +		iowrite32(0, &priv->regs->if2_id1);
>>> +		iowrite32((cf->can_id & CAN_SFF_MASK) << 2,
>>> +			   &priv->regs->if2_id2);
>>> +	}
>>> +
>>> +	pch_can_bit_set(&priv->regs->if2_id2, CAN_ID_MSGVAL);
>>
>> Do you need to do a read-modify-write of the hardware register? Please
>> prepare the values you want to write to hardware, then do it.
>>
>>> +
>>> +	/* If remote frame has to be transmitted.. */
>>> +	if (!(cf->can_id & CAN_RTR_FLAG))
>>> +		pch_can_bit_set(&priv->regs->if2_id2, CAN_ID2_DIR);
>> dito
>>> +	/* If remote frame has to be transmitted.. */
>>> +	if (cf->can_id & CAN_RTR_FLAG)
>>> +		pch_can_bit_clear(&priv->regs->if2_id2, CAN_ID2_DIR);
>> dito
>>> +
>>> +	/* Copy data to register */
>>> +	if (cf->can_dlc > 0) {
>>> +		u32 data1 = *((u16 *)&cf->data[0]);
>>> +		iowrite32(data1, &priv->regs->if2_dataa1);
>>
>> do you think you send the bytes in correct order?
>>
>>> +	}
>>> +	if (cf->can_dlc > 2) {
>>> +		u32 data1 = *((u16 *)&cf->data[2]);
>>> +		iowrite32(data1, &priv->regs->if2_dataa2);
>>> +	}
>>> +	if (cf->can_dlc > 4) {
>>> +		u32 data1 = *((u16 *)&cf->data[4]);
>>> +		iowrite32(data1, &priv->regs->if2_datab1);
>>> +	}
>>> +	if (cf->can_dlc > 6) {
>>> +		u32 data1 = *((u16 *)&cf->data[6]);
>>> +		iowrite32(data1, &priv->regs->if2_datab2);
>>> +	}
> 
> Could be handled by a loop.
> 
>>> +	can_put_echo_skb(skb, ndev, tx_buffer_avail - PCH_RX_OBJ_NUM - 1);
>>> +
>>> +	/* Set the size of the data. */
>>> +	iowrite32(cf->can_dlc, &priv->regs->if2_mcont);
>>> +
>>> +	/* Update if2_mcont */
>>> +	pch_can_bit_set(&priv->regs->if2_mcont,
>>> +			CAN_IF_MCONT_NEWDAT | CAN_IF_MCONT_TXRQXT |
>>> +			CAN_IF_MCONT_TXIE);
>>
>> pleae first perpare your value, then write to hardware.
>>
>>> +
>>> +	if (tx_buffer_avail == PCH_RX_OBJ_NUM) /* If points tail of FIFO  */
>>> +		pch_can_bit_set(&priv->regs->if2_mcont, CAN_IF_MCONT_EOB);
>>
>> dito
>>
>> Is EOB relevant for TX objects?
>>
>>> +	pch_can_check_if_busy(&priv->regs->if2_creq, tx_buffer_avail);
>>> +	spin_unlock_irqrestore(&priv->msgif_reg_lock, flags);
>>> +
>>> +	return NETDEV_TX_OK;
>>> +}
>>> +
>>> +static const struct net_device_ops pch_can_netdev_ops = {
>>> +	.ndo_open		= pch_can_open,
>>> +	.ndo_stop		= pch_close,
>>> +	.ndo_start_xmit		= pch_xmit,
>>> +};
>>> +
>>> +static void __devexit pch_can_remove(struct pci_dev *pdev)
>>> +{
>>> +	struct net_device *ndev = pci_get_drvdata(pdev);
>>> +	struct pch_can_priv *priv = netdev_priv(ndev);
>>> +
>>> +	unregister_candev(priv->ndev);
>>> +	pci_iounmap(pdev, priv->regs);
>>> +	if (priv->use_msi)
>>> +		pci_disable_msi(priv->dev);
>>> +	pci_release_regions(pdev);
>>> +	pci_disable_device(pdev);
>>> +	pci_set_drvdata(pdev, NULL);
>>> +	free_candev(priv->ndev);
>>> +}
>>> +
>>> +#ifdef CONFIG_PM
>>> +static void pch_can_set_int_custom(struct pch_can_priv *priv)
>>> +{
>>> +	/* Clearing the IE, SIE and EIE bits of Can control register. */
>>> +	pch_can_bit_clear(&priv->regs->cont, CAN_CTRL_IE_SIE_EIE);
>>> +
>>> +	/* Appropriately setting them. */
>>> +	pch_can_bit_set(&priv->regs->cont,
>>> +			((priv->int_enables & MSK_CTRL_IE_SIE_EIE) << 1));
>>> +}
>>> +
>>> +/* This function retrieves interrupt enabled for the CAN device. */
>>> +static u32 pch_can_get_int_enables(struct pch_can_priv *priv)
>>> +{
>>> +	/* Obtaining the status of IE, SIE and EIE interrupt bits. */
>>> +	return (ioread32(&priv->regs->cont) & CAN_CTRL_IE_SIE_EIE) >> 1;
>>> +}
>>> +
>>> +static u32 pch_can_get_rx_enable(struct pch_can_priv *priv, u32 buff_num)
>>> +{
>>> +	unsigned long flags;
>>> +	u32 enable;
>>> +
>>> +	spin_lock_irqsave(&priv->msgif_reg_lock, flags);
>>> +	iowrite32(CAN_CMASK_RX_TX_GET, &priv->regs->if1_cmask);
>>> +	pch_can_check_if_busy(&priv->regs->if1_creq, buff_num);
>>> +
>>> +	if (((ioread32(&priv->regs->if1_id2)) & CAN_ID_MSGVAL) &&
>>> +			((ioread32(&priv->regs->if1_mcont)) &
>>> +			CAN_IF_MCONT_RXIE))
>>> +		enable = 1;
>>> +	else
>>> +		enable = 0;
>>> +	spin_unlock_irqrestore(&priv->msgif_reg_lock, flags);
>>> +	return enable;
>>> +}
>>> +
>>> +static u32 pch_can_get_tx_enable(struct pch_can_priv *priv, u32 buff_num)
>>> +{
>>> +	unsigned long flags;
>>> +	u32 enable;
>>> +
>>> +	spin_lock_irqsave(&priv->msgif_reg_lock, flags);
>>> +
>>> +	iowrite32(CAN_CMASK_RX_TX_GET, &priv->regs->if2_cmask);
>>> +	pch_can_check_if_busy(&priv->regs->if2_creq, buff_num);
>>> +	if (((ioread32(&priv->regs->if2_id2)) & CAN_ID_MSGVAL) &&
>>> +			((ioread32(&priv->regs->if2_mcont)) &
>>> +			CAN_IF_MCONT_TXIE)) {
>>> +		enable = 1;
>>> +	} else {
>>> +		enable = 0;
>>> +	}
>>> +	spin_unlock_irqrestore(&priv->msgif_reg_lock, flags);
>>> +
>>> +	return enable;
>>> +}
> 
> The above two functions could be handled by a common one passing "struct
> pch_can_if". See similar comments above.
> 
>>> +static void pch_can_set_rx_buffer_link(struct pch_can_priv *priv,
>>> +				       u32 buffer_num, u32 set)
>>> +{
>>> +	unsigned long flags;
>>> +
>>> +	spin_lock_irqsave(&priv->msgif_reg_lock, flags);
>>> +	iowrite32(CAN_CMASK_RX_TX_GET, &priv->regs->if1_cmask);
>>> +	pch_can_check_if_busy(&priv->regs->if1_creq, buffer_num);
>>> +	iowrite32(CAN_CMASK_RDWR | CAN_CMASK_CTRL, &priv->regs->if1_cmask);
>>> +	if (set == 1)
>>> +		pch_can_bit_clear(&priv->regs->if1_mcont, CAN_IF_MCONT_EOB);
>>> +	else
>>> +		pch_can_bit_set(&priv->regs->if1_mcont, CAN_IF_MCONT_EOB);
>>> +
>>> +	pch_can_check_if_busy(&priv->regs->if1_creq, buffer_num);
>>> +	spin_unlock_irqrestore(&priv->msgif_reg_lock, flags);
>>> +}
>>> +
>>> +static u32 pch_can_get_rx_buffer_link(struct pch_can_priv *priv, u32 buffer_num)
>>> +{
>>> +	unsigned long flags;
>>> +	u32 link;
>>> +
>>> +	spin_lock_irqsave(&priv->msgif_reg_lock, flags);
>>> +	iowrite32(CAN_CMASK_RX_TX_GET, &priv->regs->if1_cmask);
>>> +	pch_can_check_if_busy(&priv->regs->if1_creq, buffer_num);
>>> +
>>> +	if (ioread32(&priv->regs->if1_mcont) & CAN_IF_MCONT_EOB)
>>> +		link = 0;
>>> +	else
>>> +		link = 1;
>>> +	spin_unlock_irqrestore(&priv->msgif_reg_lock, flags);
>>> +	return link;
>>> +}
>>> +
>>> +static int pch_can_suspend(struct pci_dev *pdev, pm_message_t state)
>>> +{
>>> +	int i;
>>> +	int retval;
>>> +	u32 buf_stat;	/* Variable for reading the transmit buffer status. */
>>> +	u32 counter = COUNTER_LIMIT;
>>> +
>>> +	struct net_device *dev = pci_get_drvdata(pdev);
>>> +	struct pch_can_priv *priv = netdev_priv(dev);
>>> +
>>> +	/* Stop the CAN controller */
>>> +	pch_can_set_run_mode(priv, PCH_CAN_STOP);
>>> +
>>> +	/* Indicate that we are aboutto/in suspend */
>>> +	priv->can.state = CAN_STATE_STOPPED;
>>> +
>>> +	/* Waiting for all transmission to complete. */
>>> +	while (counter) {
>>> +		buf_stat = pch_can_get_buffer_status(priv);
>>> +		if (!buf_stat)
>>> +			break;
>>> +		counter--;
>>> +		udelay(1);
>>> +	}
>>> +	if (!counter)
>>> +		dev_err(&pdev->dev, "%s -> Transmission time out.\n", __func__);
>>> +
>>> +	/* Save interrupt configuration and then disable them */
>>> +	priv->int_enables = pch_can_get_int_enables(priv);
>>> +	pch_can_set_int_enables(priv, PCH_CAN_DISABLE);
>>> +
>>> +	/* Save Tx buffer enable state */
>>> +	for (i = PCH_RX_OBJ_NUM + 1; i <= PCH_OBJ_NUM; i++)
>>> +		priv->tx_enable[i] = pch_can_get_tx_enable(priv, i);
>>> +
>>> +	/* Disable all Transmit buffers */
>>> +	pch_can_tx_disable_all(priv);
>>> +
>>> +	/* Save Rx buffer enable state */
>>> +	for (i = 1; i <= PCH_RX_OBJ_NUM; i++) {
>>> +		priv->rx_enable[i] = pch_can_get_rx_enable(priv, i);
>>> +		priv->rx_link[i] = pch_can_get_rx_buffer_link(priv, i);
>>> +	}
>>> +
>>> +	/* Disable all Receive buffers */
>>> +	pch_can_rx_disable_all(priv);
>>> +	retval = pci_save_state(pdev);
>>> +	if (retval) {
>>> +		dev_err(&pdev->dev, "pci_save_state failed.\n");
>>> +	} else {
>>> +		pci_enable_wake(pdev, PCI_D3hot, 0);
>>> +		pci_disable_device(pdev);
>>> +		pci_set_power_state(pdev, pci_choose_state(pdev, state));
>>> +	}
>>> +
>>> +	return retval;
>>> +}
>>> +
>>> +static int pch_can_resume(struct pci_dev *pdev)
>>> +{
>>> +	int i;
>>> +	int retval;
>>> +	struct net_device *dev = pci_get_drvdata(pdev);
>>> +	struct pch_can_priv *priv = netdev_priv(dev);
>>> +
>>> +	pci_set_power_state(pdev, PCI_D0);
>>> +	pci_restore_state(pdev);
>>> +	retval = pci_enable_device(pdev);
>>> +	if (retval) {
>>> +		dev_err(&pdev->dev, "pci_enable_device failed.\n");
>>> +		return retval;
>>> +	}
>>> +
>>> +	pci_enable_wake(pdev, PCI_D3hot, 0);
>>> +
>>> +	priv->can.state = CAN_STATE_ERROR_ACTIVE;
>>> +
>>> +	/* Disabling all interrupts. */
>>> +	pch_can_set_int_enables(priv, PCH_CAN_DISABLE);
>>> +
>>> +	/* Setting the CAN device in Stop Mode. */
>>> +	pch_can_set_run_mode(priv, PCH_CAN_STOP);
>>> +
>>> +	/* Configuring the transmit and receive buffers. */
>>> +	pch_can_config_rx_tx_buffers(priv);
>>> +
>>> +	/* Restore the CAN state */
>>> +	pch_set_bittiming(dev);
>>> +
>>> +	/* Listen/Active */
>>> +	pch_can_set_optmode(priv);
>>> +
>>> +	/* Enabling the transmit buffer. */
>>> +	for (i = 1; i <= PCH_RX_OBJ_NUM; i++)
>>> +		pch_can_set_tx_enable(priv, i, priv->tx_enable[i]);
>>> +
>>> +	/* Configuring the receive buffer and enabling them. */
>>> +	for (i = PCH_RX_OBJ_NUM + 1; i <= PCH_OBJ_NUM; i++) {
>>> +		/* Restore buffer link */
>>> +		pch_can_set_rx_buffer_link(priv, i, priv->rx_link[i]);
>>> +
>>> +		/* Restore buffer enables */
>>> +		pch_can_set_rx_enable(priv, i, priv->rx_enable[i]);
>>> +	}
>>> +
>>> +	/* Enable CAN Interrupts */
>>> +	pch_can_set_int_custom(priv);
>>> +
>>> +	/* Restore Run Mode */
>>> +	pch_can_set_run_mode(priv, PCH_CAN_RUN);
>>> +
>>> +	return retval;
>>> +}
>>> +#else
>>> +#define pch_can_suspend NULL
>>> +#define pch_can_resume NULL
>>> +#endif
>>> +
>>> +static int pch_can_get_berr_counter(const struct net_device *dev,
>>> +				    struct can_berr_counter *bec)
>>> +{
>>> +	struct pch_can_priv *priv = netdev_priv(dev);
>>> +
>>> +	bec->txerr = ioread32(&priv->regs->errc) & CAN_TEC;
>>> +	bec->rxerr = (ioread32(&priv->regs->errc) & CAN_REC) >> 8;
>>> +
>>> +	return 0;
>>> +}
>>> +
>>> +static int __devinit pch_can_probe(struct pci_dev *pdev,
>>> +				   const struct pci_device_id *id)
>>> +{
>>> +	struct net_device *ndev;
>>> +	struct pch_can_priv *priv;
>>> +	int rc;
>>> +	void __iomem *addr;
>>> +
>>> +	rc = pci_enable_device(pdev);
>>> +	if (rc) {
>>> +		dev_err(&pdev->dev, "Failed pci_enable_device %d\n", rc);
>>> +		goto probe_exit_endev;
>>> +	}
>>> +
>>> +	rc = pci_request_regions(pdev, KBUILD_MODNAME);
>>> +	if (rc) {
>>> +		dev_err(&pdev->dev, "Failed pci_request_regions %d\n", rc);
>>> +		goto probe_exit_pcireq;
>>> +	}
>>> +
>>> +	addr = pci_iomap(pdev, 1, 0);
>>> +	if (!addr) {
>>> +		rc = -EIO;
>>> +		dev_err(&pdev->dev, "Failed pci_iomap\n");
>>> +		goto probe_exit_ipmap;
>>> +	}
>>> +
>>> +	ndev = alloc_candev(sizeof(struct pch_can_priv), PCH_TX_OBJ_NUM);
>>> +	if (!ndev) {
>>> +		rc = -ENOMEM;
>>> +		dev_err(&pdev->dev, "Failed alloc_candev\n");
>>> +		goto probe_exit_alloc_candev;
>>> +	}
>>> +
>>> +	priv = netdev_priv(ndev);
>>> +	priv->ndev = ndev;
>>> +	priv->regs = addr;
>>> +	priv->dev = pdev;
>>> +	priv->can.bittiming_const = &pch_can_bittiming_const;
>>> +	priv->can.do_set_mode = pch_can_do_set_mode;
>>> +	priv->can.do_get_berr_counter = pch_can_get_berr_counter;
>>> +	priv->can.ctrlmode_supported = CAN_CTRLMODE_LISTENONLY |
>>> +				       CAN_CTRLMODE_LOOPBACK;
> 
> I'm missing CAN_CTRLMODE_3_SAMPLES here?
> 
>>> +	priv->tx_obj = PCH_RX_OBJ_NUM + 1; /* Point head of Tx Obj */
>>> +
>>> +	ndev->irq = pdev->irq;
>>> +	ndev->flags |= IFF_ECHO;
>>> +
>>> +	pci_set_drvdata(pdev, ndev);
>>> +	SET_NETDEV_DEV(ndev, &pdev->dev);
>>> +	ndev->netdev_ops = &pch_can_netdev_ops;
>>> +	priv->can.clock.freq = PCH_CAN_CLK; /* Hz */
>>> +
>>> +	netif_napi_add(ndev, &priv->napi, pch_can_rx_poll, PCH_RX_OBJ_NUM);
>>> +
>>> +	rc = pci_enable_msi(priv->dev);
>>> +	if (rc) {
>>> +		dev_info(&ndev->dev, "PCH CAN opened without MSI\n");
>>> +		priv->use_msi = 0;
>>> +	} else {
>>> +		dev_info(&ndev->dev, "PCH CAN opened with MSI\n");
>>> +		priv->use_msi = 1;
>>> +	}
>>> +
>>> +	rc = register_candev(ndev);
>>> +	if (rc) {
>>> +		dev_err(&pdev->dev, "Failed register_candev %d\n", rc);
>>> +		goto probe_exit_reg_candev;
>>> +	}
>>> +
>>> +	return 0;
>>> +
>>> +probe_exit_reg_candev:
>>> +	free_candev(ndev);
>>> +probe_exit_alloc_candev:
>>> +	pci_iounmap(pdev, addr);
>>> +probe_exit_ipmap:
>>> +	pci_release_regions(pdev);
>>> +probe_exit_pcireq:
>>> +	pci_disable_device(pdev);
>>> +probe_exit_endev:
>>> +	return rc;
>>> +}
>>> +
>>> +static struct pci_driver pch_can_pcidev = {
>>> +	.name = "pch_can",
>>> +	.id_table = pch_pci_tbl,
>>> +	.probe = pch_can_probe,
>>> +	.remove = __devexit_p(pch_can_remove),
>>> +	.suspend = pch_can_suspend,
>>> +	.resume = pch_can_resume,
>>> +};
>>> +
>>> +static int __init pch_can_pci_init(void)
>>> +{
>>> +	return pci_register_driver(&pch_can_pcidev);
>>> +}
>>> +module_init(pch_can_pci_init);
>>> +
>>> +static void __exit pch_can_pci_exit(void)
>>> +{
>>> +	pci_unregister_driver(&pch_can_pcidev);
>>> +}
>>> +module_exit(pch_can_pci_exit);
>>> +
>>> +MODULE_DESCRIPTION("Intel EG20T PCH CAN(Controller Area Network) Driver");
>>> +MODULE_LICENSE("GPL v2");
>>> +MODULE_VERSION("0.94");
> 
> As the driver has already been merged. Please provide incremental
> patches against the net-2.6 branch. Also, it would be nice if you could
> check in-order transmission and reception, e.g., with the can-utils
> program canfdtest:
> 
> http://svn.berlios.de/wsvn/socketcan/trunk/can-utils/canfdtest.c
> 
> Thanks,
> 
> Wolfgang.
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cheers, Marc

-- 
Pengutronix e.K.                  | Marc Kleine-Budde           |
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