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From: Wolfgang Grandegger <wg@grandegger.com>
To: "Lothar Waßmann" <LW@KARO-electronics.de>
Cc: Marc Kleine-Budde <mkl@pengutronix.de>,
	linux-can@vger.kernel.org, netdev@vger.kernel.org,
	linux-kernel@vger.kernel.org
Subject: Re: [PATCH] flexcan: Acknowledge all interrupt sources in the IRQ handler
Date: Fri, 09 Dec 2011 15:35:02 +0100	[thread overview]
Message-ID: <4EE21C96.5010604@grandegger.com> (raw)
In-Reply-To: <20194.5210.650914.867608@ipc1.ka-ro>

On 12/09/2011 02:59 PM, Lothar Waßmann wrote:
> Hi,
> 
> Marc Kleine-Budde writes:
>> On 12/09/2011 02:47 PM, Lothar Waßmann wrote:
>>> Otherwise the handler will get stuck in an endless IRQ loop when an
>>> interrupt condition occurs that is not being acked (e.g. TWRN)
>>
>> On which CPU do you have this problem?
>>
> on i.MX28.

Yes, it is definitely needed on i.MX28 and I already have it in my
series. See:

https://gitorious.org/~wgrandegger/linux-can/wg-linux-can-next/commit/8ad94fa0dd7f7728824fa8fd4479390ac3f189c7

BTW: at similar patch was already sent by Reuben Dowle.

>> Seems that mx25/35 behave a bit different than mx28. But I had no time
>> to dig into this, yet. BTW Wolfgang is just reworking error handling,
>> can you please test his patches he recently posted on linux-can.
>>
> The ESR of i.MX25 is completely identical to the i.MX28.
> You should be able to reproduce the problem when trying to send a
> message to a CAN interface with the transceiver disabled.
> You will get a BIT0_ERR and the TWRN bit will be asserted and never
> cleared leading to an endless interrupt loop.

If you are right, the code was never working on i.MX25/35... which I doubt.

Wolfgang.

  reply	other threads:[~2011-12-09 14:35 UTC|newest]

Thread overview: 5+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2011-12-09 13:47 [PATCH] flexcan: Acknowledge all interrupt sources in the IRQ handler Lothar Waßmann
2011-12-09 13:52 ` Marc Kleine-Budde
2011-12-09 13:59   ` Lothar Waßmann
2011-12-09 14:35     ` Wolfgang Grandegger [this message]
2011-12-10 20:10       ` Wolfgang Grandegger

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