From: "Thomas Mühlbacher" <tmuehlbacher@posteo.net>
To: Marc Kleine-Budde <mkl@pengutronix.de>
Cc: linux-can@vger.kernel.org, Vincent Mailhol <mailhol.vincent@wanadoo.fr>
Subject: Re: [PATCH] can: sja1000: fix max irq loop handling
Date: Mon, 17 Nov 2025 22:15:44 +0000 [thread overview]
Message-ID: <875xb8b90w.fsf@posteo.net> (raw)
In-Reply-To: <20251116-inescapable-festive-kiwi-40724d-mkl@pengutronix.de> (Marc Kleine-Budde's message of "Sun, 16 Nov 2025 16:25:33 +0100")
Thanks for reviewing.
Marc Kleine-Budde <mkl@pengutronix.de> writes:
> On 15.11.2025 15:34:56, Thomas Mühlbacher wrote:
>> Reading the interrupt register `SJA1000_IR` causes all of its bits to be
>> reset. If we ever reach the condition of handling more than
>> `SJA1000_MAX_IRQ` IRQs, we will have read the register and reset all its
>> bits but without actually handling the interrupt inside of the loop
>> body.
>>
>> This may, among other issues, cause us to never `netif_wake_queue()`
>> again after a transmission interrupt.
>
> Applied to linux-can and added stable to Cc. Out of curiosity, what
> hardware are you using that has an SJA1000 IP core built in?
It's a B&R APC3200, relying on the sja1000_isa module. Currently
debugging something there. However, this I actually found from staring
at the code and data sheet for a while.
Best,
Thomas
prev parent reply other threads:[~2025-11-17 22:15 UTC|newest]
Thread overview: 4+ messages / expand[flat|nested] mbox.gz Atom feed top
2025-11-15 15:34 [PATCH] can: sja1000: fix max irq loop handling Thomas Mühlbacher
2025-11-15 16:43 ` Oliver Hartkopp
2025-11-16 15:25 ` Marc Kleine-Budde
2025-11-17 22:15 ` Thomas Mühlbacher [this message]
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