Subject: Re: [PATCH net-next 1/3] net: stmmac: add gmac autoneg set for SGMII, TBI, and RTBI

From: Giuseppe CAVALLARO <[email-masked]>
Date: Wed, 16 Jan 2013 08:28:13 +0100

Hello Byungho,

On 1/15/2013 10:45 PM, Byungho An wrote:
>
> This patch adds gmac autoneg set function for SGMII, TBI,
> or RTBI interface. In case of PHY's autoneg is set, gmac's
> autoneg enable bit should set. After checking phy's autoneg
> if phydev's autoneg is '1' gmac's ANE bit set for those
> interface.

Sorry I've some doubts about these patches.

Firstly if the MAC is able to manage RGMII/SGMII etc this should be 
verified by looking at the HW cap register: i.e. PCS bit.

   (I have no HW that support this so I cannot do any tests).

In case of this feature is actually supported then the driver could
manage everything bypassing the MDIO.
IMO, we could not need to call the stmmac_phy_init and we should not
use the PHYLIB.
I mean if we have the PCS module we could have a minimal support to get
link status, restart ANE etc w/o using at all the PHYLIB (so w/o 
touching the PHY regs via the MDIO/MDC).

   It could also be useful to complete the support with the RGMII... no
   extra effort should be needed while adding SGMII if you look at the
   core registers.
   If you add the RGMII on some platforms we could guarantee to manage
   the fix_mac_speed (see stmmac doc).

Looking at the other your patches, the ethtool support is not
completed. I expected to restart ANE, get/set link property etc.

Also pay attention to properly treat EEE. Maybe, as first stage we
should disable the feature in this case. We will see it later.
The question is that we could not be able to use some extra features
that currently need to dialog more with the PHY device. I mean what we
actually do by using PHYLIB.

>
> Signed-off-by: Byungho An <[email-masked]>
> ---
>   drivers/net/ethernet/stmicro/stmmac/common.h         |    1 +
>   drivers/net/ethernet/stmicro/stmmac/dwmac1000_core.c |   11 +++++++++++
>   drivers/net/ethernet/stmicro/stmmac/stmmac_main.c    |    9 +++++++++
>   3 files changed, 21 insertions(+)
>
> diff --git a/drivers/net/ethernet/stmicro/stmmac/common.h
> b/drivers/net/ethernet/stmicro/stmmac/common.h
> index 186d148..72ba769 100644
> --- a/drivers/net/ethernet/stmicro/stmmac/common.h
> +++ b/drivers/net/ethernet/stmicro/stmmac/common.h
> @@ -344,6 +344,7 @@ struct stmmac_ops {
>   	void (*reset_eee_mode) (void __iomem *ioaddr);
>   	void (*set_eee_timer) (void __iomem *ioaddr, int ls, int tw);
>   	void (*set_eee_pls) (void __iomem *ioaddr, int link);
> +	void (*set_autoneg) (void __iomem *ioaddr);
>   };
>
>   struct mac_link {
> diff --git a/drivers/net/ethernet/stmicro/stmmac/dwmac1000_core.c
> b/drivers/net/ethernet/stmicro/stmmac/dwmac1000_core.c
> index bfe0226..a0737b39 100644
> --- a/drivers/net/ethernet/stmicro/stmmac/dwmac1000_core.c
> +++ b/drivers/net/ethernet/stmicro/stmmac/dwmac1000_core.c
> @@ -297,6 +297,16 @@ static void  dwmac1000_set_eee_timer(void __iomem
> *ioaddr, int ls, int tw)
>   	writel(value, ioaddr + LPI_TIMER_CTRL);
>   }
>
> +static void dwmac1000_set_autoneg(void __iomem *ioaddr)
> +{
> +	u32 value;
> +
> +	value = readl(ioaddr + GMAC_AN_CTRL);
> +	value |= 0x1000;

pls use define instead of raw values ... see below.

> +	writel(value, ioaddr + GMAC_AN_CTRL);
> +}
> +
> +
>   static const struct stmmac_ops dwmac1000_ops = {
>   	.core_init = dwmac1000_core_init,
>   	.rx_ipc = dwmac1000_rx_ipc_enable,
> @@ -311,6 +321,7 @@ static const struct stmmac_ops dwmac1000_ops = {
>   	.reset_eee_mode =  dwmac1000_reset_eee_mode,
>   	.set_eee_timer =  dwmac1000_set_eee_timer,
>   	.set_eee_pls =  dwmac1000_set_eee_pls,
> +	.set_autoneg =  dwmac1000_set_autoneg,
>   };
>
>   struct mac_device_info *dwmac1000_setup(void __iomem *ioaddr)
> diff --git a/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
> b/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
> index f07c061..3e28934 100644
> --- a/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
> +++ b/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
> @@ -1007,6 +1007,7 @@ static int stmmac_open(struct net_device *dev)
>   {
>   	struct stmmac_priv *priv = netdev_priv(dev);
>   	int ret;
> +	int interface = priv->plat->interface;
>
>   	clk_prepare_enable(priv->stmmac_clk);
>
> @@ -1041,6 +1042,14 @@ static int stmmac_open(struct net_device *dev)
>   	/* Initialize the MAC Core */
>   	priv->hw->mac->core_init(priv->ioaddr);
>
> +	/* If phy autoneg is on, set gmac autoneg for SGMII, TBI and RTBI*/
> +	if (interface == PHY_INTERFACE_MODE_SGMII ||
> +	    interface == PHY_INTERFACE_MODE_TBI ||
> +	    interface == PHY_INTERFACE_MODE_RTBI) {
> +		if (priv->phydev->autoneg)
> +			priv->hw->mac->set_autoneg(priv->ioaddr);
> +	}

we could use the following instead of priv->hw->mac->set_autoneg:

static void dwmac1000_ctrl_ane(void __iomem *ioaddr, bool restart)
{
     int value = GMAC_CTRL_ANE_EN;

     if (restart)
         value |= GMAC_CTRL_ANE_RESTART;

     writel(value, ioaddr +GMAC_AN_CTRL);
}

where we should defines all the missing macros for the registers 48, 49 ...

/* RGMI/SGMII defines */
#define GMAC_CTRL_ANE_SGMII_RAL (1 << 18)
#define GMAC_CTRL_ANE_EN       (1 << 12)
#define GMAC_CTRL_ANE_RESTART  (1 << 9)

The handler should store the link status that will be used to pass the 
info to the ethtool for example. We need to manage speed and duplex etc.

What happens if you run "ethtool eth0" command?
Or if you run mii-tool?
I expect to get the right speed and duplex at least.

Concerning the stmmac_set_pauseparam I'm also not sure you are doing the 
right thing. Note that you are not restarting the ANE at all ... (this 
is what the phy_start_aneg does). If set the bit 12 then you are 
enabling the ane. To restart it, you need to set the bit 9 in the reg 48.

I can support you on all the points above. Let me know.

BR,
peppe

> +
>   	/* Request the IRQ lines */
>   	ret = request_irq(dev->irq, stmmac_interrupt,
>   			 IRQF_SHARED, dev->name, dev);
>