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, 15 Jul 2010 12:21:30 +0200 [thread overview]
Message-ID: <4C3EE12A.1030307@grandegger.com> (raw)
In-Reply-To: <4C3EDDB1.5040109-bIcnvbaLZ9MEGnE8C9+IrQ@public.gmane.org>
On 07/15/2010 12:06 PM, Marc Kleine-Budde wrote:
> Hey Wolfgang,
>
> Wolfgang Grandegger wrote:
>>> This core is found on some Freescale SoCs and also some Coldfire
>>> SoCs. Support for Coldfire is missing though at the moment as
>>> they have an older revision of the core which does not have RX FIFO
>>> support.
>>>
>>> Signed-off-by: Sascha Hauer <s.hauer-bIcnvbaLZ9MEGnE8C9+IrQ@public•gmane.org>
>>> Signed-off-by: Marc Kleine-Budde <mkl-bIcnvbaLZ9MEGnE8C9+IrQ@public•gmane.org>
>>> ---
>>>
>>> Changes to prev version:
>>> * The is now GPLv2 (only) as no one complained.
>>>
>>> The patch applies to current net-next-2.6/master.
>>> If there aren't any objections please consider applying this patch.
>>> Wolfgang, can I an Acked-by?
>>
>> I already had a look to the previous version and I realized that
>> accessing reg_esr is racy. I will dig out my notes and come up with a
>> full review later today or tomorrow.
>
> Let me have a look....
>
> I think I should remove the read reg_esr in "flexcan_irq_err()" and use
> the value read in "flexcan_irq()"
>
> Without the fix, there's a race window that we loose some error bits
> from the interrupt handler to the napi function, because the error bits
> are cleared on read.
Right, that is my concern. reg_esr should only be read and handled
*once*. Currently it's read *3* times! I would read it in the ISR and
handle it in the NAPI poll function, including state change
notification. But I need a closer look...
> Regarding the upcoming improvement of the can error frames upon state
> changes, I'd first like to get this driver merged and then discuss a
> solution for the error frames.
Fine for me. I'm currently preparing a RFC patch for SJA1000 and MSCAN.
Wolfgang.
next prev parent reply other threads:[~2010-07-15 10:21 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 [this message]
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
[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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