From: Wolfgang Grandegger <wg-5Yr1BZd7O62+XT7JhA+gdA@public•gmane.org>
To: Marc Kleine-Budde <mkl-bIcnvbaLZ9MEGnE8C9+IrQ@public•gmane.org>
Cc: socketcan-core-0fE9KPoRgkgATYTw5x5z8w@public•gmane.org,
netdev-u79uwXL29TY76Z2rM5mHXA@public•gmane.org
Subject: Re: [PATCH] CAN: Add Flexcan CAN controller driver
Date: Thu, 22 Jul 2010 11:25:18 +0200 [thread overview]
Message-ID: <4C480E7E.70607@grandegger.com> (raw)
In-Reply-To: <4C475BA6.3030505-bIcnvbaLZ9MEGnE8C9+IrQ@public.gmane.org>
On 07/21/2010 10:42 PM, Marc Kleine-Budde wrote:
> Marc Kleine-Budde wrote:
>> Wolfgang Grandegger wrote:
>>> I realized a few issues. You can add my "acked-by" when they are fixed.
>>
>> thanks for the review.
>
> [...]
>
>>>> +static void flexcan_poll_err_frame(struct net_device *dev,
>>>> + struct can_frame *cf, u32 reg_esr)
>>>> +{
>>>> + struct flexcan_priv *priv = netdev_priv(dev);
>>>> + int error_warning = 0, rx_errors = 0, tx_errors = 0;
>>>> +
>>>> + if (reg_esr & FLEXCAN_ESR_BIT1_ERR) {
>>>> + rx_errors = 1;
>>>> + cf->can_id |= CAN_ERR_PROT | CAN_ERR_BUSERROR;
>>>> + cf->data[2] |= CAN_ERR_PROT_BIT1;
>>>> + }
>>>> +
>>>> + if (reg_esr & FLEXCAN_ESR_BIT0_ERR) {
>>>> + rx_errors = 1;
>>>> + cf->can_id |= CAN_ERR_PROT | CAN_ERR_BUSERROR;
>>>> + cf->data[2] |= CAN_ERR_PROT_BIT0;
>>>> + }
>>>> +
>>>> + if (reg_esr & FLEXCAN_ESR_FRM_ERR) {
>>>> + rx_errors = 1;
>>>> + cf->can_id |= CAN_ERR_PROT | CAN_ERR_BUSERROR;
>>>> + cf->data[2] |= CAN_ERR_PROT_FORM;
>>>> + }
>>>> +
>>>> + if (reg_esr & FLEXCAN_ESR_STF_ERR) {
>>>> + rx_errors = 1;
>>>> + cf->can_id |= CAN_ERR_PROT | CAN_ERR_BUSERROR;
>>>> + cf->data[2] |= CAN_ERR_PROT_STUFF;
>>>> + }
>>>> +
>>>> +
>>>> + if (reg_esr & FLEXCAN_ESR_ACK_ERR) {
>>>> + tx_errors = 1;
>>>> + cf->can_id |= CAN_ERR_ACK;
>>> This is a bus-error as well. Therefore I think it should be:
>>>
>>> if (reg_esr & FLEXCAN_ESR_ACK_ERR) {
>>> tx_errors = 1;
>>> cf->can_id |= CAN_ERR_ACK;
>>> cf->can_id |= CAN_ERR_PROT | CAN_ERR_BUSERROR;
>>> cf->data[3] |= CAN_ERR_PROT_LOC_ACK; /* ACK slot */
>>> }
>>>
>>> I need to check what CAN_ERR_ACK is intended for. Then, cf->can_id could
>>> be preset with "CAN_ERR_PROT | CAN_ERR_BUSERROR" at the beginning.
>
> This controller issues an ACK error if there are no other nodes on the
> CAN bus to send a ACK that the message has been received. Or all
> remaining Nodes are in bus off state.
Mainly this bus error can cause the infamous IRQ and message flooding
when no cable is connected.
> From the datasheet:
> "This bit indicates that an acknowledge (ACK) error has been detected by
> the transmitter node; that is, a dominant bit has not been detected
> during the ACK SLOT."
That's what the above error describes, like on the SJA1000, apart from
setting CAN_ERR_ACK. Setting CAN_ERR_ACK is somehow bogus, but just
leave it for the time being. I will fix it globally when time permits.
Wolfgang.
next prev parent reply other threads:[~2010-07-22 9:25 UTC|newest]
Thread overview: 16+ messages / expand[flat|nested] mbox.gz Atom feed top
2010-07-14 22:00 [PATCH] CAN: Add Flexcan CAN controller driver Marc Kleine-Budde
[not found] ` <1279144811-12251-1-git-send-email-mkl-bIcnvbaLZ9MEGnE8C9+IrQ@public.gmane.org>
2010-07-15 9:37 ` Wolfgang Grandegger
[not found] ` <4C3ED6F5.7040606-5Yr1BZd7O62+XT7JhA+gdA@public.gmane.org>
2010-07-15 10:06 ` Marc Kleine-Budde
[not found] ` <4C3EDDB1.5040109-bIcnvbaLZ9MEGnE8C9+IrQ@public.gmane.org>
2010-07-15 10:21 ` Wolfgang Grandegger
2010-07-15 18:38 ` Wolfgang Grandegger
[not found] ` <4C3F55A9.8030307-5Yr1BZd7O62+XT7JhA+gdA@public.gmane.org>
2010-07-16 13:21 ` Marc Kleine-Budde
[not found] ` <4C405CEC.3000701-bIcnvbaLZ9MEGnE8C9+IrQ@public.gmane.org>
2010-07-21 20:42 ` Marc Kleine-Budde
[not found] ` <4C475BA6.3030505-bIcnvbaLZ9MEGnE8C9+IrQ@public.gmane.org>
2010-07-22 9:25 ` Wolfgang Grandegger [this message]
[not found] ` <4C480E7E.70607-5Yr1BZd7O62+XT7JhA+gdA@public.gmane.org>
2010-07-22 9:33 ` Marc Kleine-Budde
[not found] ` <4C481064.8090809-bIcnvbaLZ9MEGnE8C9+IrQ@public.gmane.org>
2010-07-22 9:44 ` Wolfgang Grandegger
-- strict thread matches above, loose matches on Subject: below --
2010-07-22 16:40 Marc Kleine-Budde
2010-07-22 19:29 ` David Miller
2010-07-25 11:24 ` Oliver Hartkopp
2010-07-25 12:01 ` Marc Kleine-Budde
2010-06-17 14:21 Marc Kleine-Budde
[not found] ` <1276784480-32340-1-git-send-email-mkl-bIcnvbaLZ9MEGnE8C9+IrQ@public.gmane.org>
2010-06-17 19:12 ` Wolfgang Grandegger
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