From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mout01.posteo.de (mout01.posteo.de [185.67.36.65]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 8D81523EABB for ; Mon, 17 Nov 2025 22:15:46 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=185.67.36.65 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1763417748; cv=none; b=ld9c4t4+r/b6GnubUTGYQEBo70IrAkRUMQ0uU/34e2H42hgR5617ijEkJOGt+WY67HSKrFroyRD1pUV82fZy8ya4UrVFcRVER4CJIGHLko9WgAFn5bQW1q8w/upRrTL71t56bAso9bm8X5VpR2UW+qW84Ju/y6bzKTGLQbWHlqg= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1763417748; c=relaxed/simple; bh=Z+J/p00XcyZO+ov4fpGwnpvMmWcSBc2AMJMrvGxidv8=; h=From:To:Cc:Subject:In-Reply-To:References:Date:Message-ID: MIME-Version:Content-Type; b=Vx6ho1cN+MJ5QeDOyVc/rprW6lC1i9h8cIr58LOiRFM/KZm7OC6XtAq00SbwxmhS+0lO/c1NNqnjwkejJy1wijABtQ9P1OKkWIqQfjQEkg5GaWnBXl5vhsJ4fOcNYxp130DWVXYdP61iaj4kUG8rmpJER5GqgACB83y1U1yciAw= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=posteo.net; spf=pass smtp.mailfrom=posteo.net; dkim=pass (2048-bit key) header.d=posteo.net header.i=@posteo.net header.b=f0eh4p0x; arc=none smtp.client-ip=185.67.36.65 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=posteo.net Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=posteo.net Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=posteo.net header.i=@posteo.net header.b="f0eh4p0x" Received: from submission (posteo.de [185.67.36.169]) by mout01.posteo.de (Postfix) with ESMTPS id B5F6B240028 for ; Mon, 17 Nov 2025 23:15:44 +0100 (CET) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=posteo.net; s=2017; t=1763417744; bh=Z+J/p00XcyZO+ov4fpGwnpvMmWcSBc2AMJMrvGxidv8=; h=From:To:Cc:Subject:Date:Message-ID:MIME-Version:Content-Type: Content-Transfer-Encoding:From; b=f0eh4p0x6zPEweP/WnxptPnF52xP/UWd6k4wvd25tH0RJb+5LfkDNtUSXA9wIN1BE JZOkSoNwnAIT3343116/RJt4nonH5fVC2dgXg6XcEWXhJuuVnNQ2rMaVPtfjnoc0AH 0CXARUcRh2o0m7og5yj65oQ0R41hszKamMD6qMxaUx649Scbv3TEu5nw5MwZzBD9qI xYmlrzdOBD5BVWhY4PgHMqv2xh1QAEqd/1bA1+R1TST5v9XCfVp31h8QmYWN6Ic5tC CGZTDw4by5eZRoTwnTFMZJkqGCGeSZXozcmfTn7jTIWuNfBaU2Q2Xz+WE2NTsi9TNr 0mPeN9JnRRbHw== Received: from customer (localhost [127.0.0.1]) by submission (posteo.de) with ESMTPSA id 4d9MWh0V46z9rxF; Mon, 17 Nov 2025 23:15:44 +0100 (CET) From: =?utf-8?Q?Thomas_M=C3=BChlbacher?= To: Marc Kleine-Budde Cc: linux-can@vger.kernel.org, Vincent Mailhol Subject: Re: [PATCH] can: sja1000: fix max irq loop handling 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") References: <20251115153437.11419-1-tmuehlbacher@posteo.net> <20251116-inescapable-festive-kiwi-40724d-mkl@pengutronix.de> Date: Mon, 17 Nov 2025 22:15:44 +0000 Message-ID: <875xb8b90w.fsf@posteo.net> Precedence: bulk X-Mailing-List: linux-can@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: quoted-printable Thanks for reviewing. Marc Kleine-Budde writes: > On 15.11.2025 15:34:56, Thomas M=C3=BChlbacher 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