Message ID | 20220818203308.439043-2-nicolas.dufresne@collabora.com (mailing list archive) |
---|---|
State | Accepted |
Delegated to: | Hans Verkuil |
Headers |
Received: from vger.kernel.org ([23.128.96.18]) by www.linuxtv.org with esmtp (Exim 4.92) (envelope-from <linux-media-owner@vger.kernel.org>) id 1oOmDG-006F8A-6k; Thu, 18 Aug 2022 20:33:58 +0000 Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1344677AbiHRUd4 (ORCPT <rfc822;mkrufky@linuxtv.org> + 1 other); Thu, 18 Aug 2022 16:33:56 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:52626 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S238275AbiHRUdy (ORCPT <rfc822;linux-media@vger.kernel.org>); Thu, 18 Aug 2022 16:33:54 -0400 Received: from madras.collabora.co.uk (madras.collabora.co.uk [IPv6:2a00:1098:0:82:1000:25:2eeb:e5ab]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 12EE633A0E; Thu, 18 Aug 2022 13:33:51 -0700 (PDT) Received: from whitebuilder.lan (192-222-136-102.qc.cable.ebox.net [192.222.136.102]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (4096 bits) server-digest SHA256) (No client certificate requested) (Authenticated sender: nicolas) by madras.collabora.co.uk (Postfix) with ESMTPSA id 026F96601B46; Thu, 18 Aug 2022 21:33:47 +0100 (BST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=collabora.com; s=mail; t=1660854830; bh=pggMW/0Bxy8VjFzlvpemyaipfIDNrL2BmOAkso3LhhQ=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=V2yfagMG57Nh3EXsVf9/Smr/3esiSEbIWwaYOIiLAHA+6nV2niIE9P/2HYaJiywov G8QzDCDnzOeAeslg/Tnf6Y9Fa3il7jyPDhLjVbM7IVs/H25Cncmgrkt9lNIanNMXIH osCQAXJsYJM/LZFnYttXjTZGnrlrEAZGby67oDBvlz6EPuX9kn5AGAraiJ8vISeafA KZV1o2iv9NY/0c63k5T/OFe3i3YohHc1x0KoPwBvSjXyfhTNG0GaSs3gFmR3bVKV1j rwpyCFPLSBmjLyK3NVkNNEQlz6x/P9B6B1wKrascvZhZh9JV39AGv6CnYK47ccsQ/a wNOz5rtW8yh6Q== From: Nicolas Dufresne <nicolas.dufresne@collabora.com> To: linux-media@vger.kernel.org, Maxime Ripard <mripard@kernel.org>, Paul Kocialkowski <paul.kocialkowski@bootlin.com>, Mauro Carvalho Chehab <mchehab@kernel.org>, Greg Kroah-Hartman <gregkh@linuxfoundation.org>, Chen-Yu Tsai <wens@csie.org>, Jernej Skrabec <jernej.skrabec@gmail.com>, Samuel Holland <samuel@sholland.org>, Ezequiel Garcia <ezequiel@vanguardiasur.com.ar>, Hans Verkuil <hverkuil-cisco@xs4all.nl> Cc: kernel@collabora.com, Nicolas Dufresne <nicolas.dufresne@collabora.com>, stable@vger.kernel.org, linux-staging@lists.linux.dev, linux-arm-kernel@lists.infradead.org, linux-sunxi@lists.linux.dev, linux-kernel@vger.kernel.org Subject: [PATCH v1 1/3] media: cedrus: Fix watchdog race condition Date: Thu, 18 Aug 2022 16:33:06 -0400 Message-Id: <20220818203308.439043-2-nicolas.dufresne@collabora.com> X-Mailer: git-send-email 2.37.2 In-Reply-To: <20220818203308.439043-1-nicolas.dufresne@collabora.com> References: <20220818203308.439043-1-nicolas.dufresne@collabora.com> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Spam-Status: No, score=-2.1 required=5.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,DKIM_VALID_EF,SPF_HELO_NONE,SPF_PASS, T_SCC_BODY_TEXT_LINE,URIBL_BLOCKED autolearn=ham autolearn_force=no version=3.4.6 X-Spam-Checker-Version: SpamAssassin 3.4.6 (2021-04-09) on lindbergh.monkeyblade.net Precedence: bulk List-ID: <linux-media.vger.kernel.org> X-Mailing-List: linux-media@vger.kernel.org X-LSpam-Score: -2.5 (--) X-LSpam-Report: No, score=-2.5 required=5.0 tests=BAYES_00=-1.9,DKIM_SIGNED=0.1,DKIM_VALID=-0.1,DKIM_VALID_AU=-0.1,HEADER_FROM_DIFFERENT_DOMAINS=0.5,MAILING_LIST_MULTI=-1 autolearn=ham autolearn_force=no |
Series |
cedrus: Various bug fixes
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Commit Message
Nicolas Dufresne
Aug. 18, 2022, 8:33 p.m. UTC
The watchdog needs to be schedule before we trigger the decode
operation, otherwise there is a risk that the decoder IRQ will be
called before we have schedule the watchdog. As a side effect, the
watchdog would never be cancelled and its function would be called
at an inappropriate time.
This was observed while running Fluster with GStreamer as a backend.
Some programming error would cause the decoder IRQ to be call very
quickly after the trigger. Later calls into the driver would deadlock
due to the unbalanced state.
Cc: stable@vger.kernel.org
Fixes: 7c38a551bda1 ("media: cedrus: Add watchdog for job completion")
Signed-off-by: Nicolas Dufresne <nicolas.dufresne@collabora.com>
---
drivers/staging/media/sunxi/cedrus/cedrus_dec.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)
Comments
Hi Nicolas, On Thu 18 Aug 22, 16:33, Nicolas Dufresne wrote: > The watchdog needs to be schedule before we trigger the decode > operation, otherwise there is a risk that the decoder IRQ will be > called before we have schedule the watchdog. As a side effect, the > watchdog would never be cancelled and its function would be called > at an inappropriate time. > > This was observed while running Fluster with GStreamer as a backend. > Some programming error would cause the decoder IRQ to be call very > quickly after the trigger. Later calls into the driver would deadlock > due to the unbalanced state. Good catch, thanks! Reviewed-by: Paul Kocialkowski <paul.kocialkowski@bootlin.com> Cheers, Paul > Cc: stable@vger.kernel.org > Fixes: 7c38a551bda1 ("media: cedrus: Add watchdog for job completion") > Signed-off-by: Nicolas Dufresne <nicolas.dufresne@collabora.com> > --- > drivers/staging/media/sunxi/cedrus/cedrus_dec.c | 4 ++-- > 1 file changed, 2 insertions(+), 2 deletions(-) > > diff --git a/drivers/staging/media/sunxi/cedrus/cedrus_dec.c b/drivers/staging/media/sunxi/cedrus/cedrus_dec.c > index 3b6aa78a2985f..e7f7602a5ab40 100644 > --- a/drivers/staging/media/sunxi/cedrus/cedrus_dec.c > +++ b/drivers/staging/media/sunxi/cedrus/cedrus_dec.c > @@ -106,11 +106,11 @@ void cedrus_device_run(void *priv) > > /* Trigger decoding if setup went well, bail out otherwise. */ > if (!error) { > - dev->dec_ops[ctx->current_codec]->trigger(ctx); > - > /* Start the watchdog timer. */ > schedule_delayed_work(&dev->watchdog_work, > msecs_to_jiffies(2000)); > + > + dev->dec_ops[ctx->current_codec]->trigger(ctx); > } else { > v4l2_m2m_buf_done_and_job_finish(ctx->dev->m2m_dev, > ctx->fh.m2m_ctx, > -- > 2.37.2 >
Dne četrtek, 18. avgust 2022 ob 22:33:06 CEST je Nicolas Dufresne napisal(a): > The watchdog needs to be schedule before we trigger the decode > operation, otherwise there is a risk that the decoder IRQ will be > called before we have schedule the watchdog. As a side effect, the > watchdog would never be cancelled and its function would be called > at an inappropriate time. > > This was observed while running Fluster with GStreamer as a backend. > Some programming error would cause the decoder IRQ to be call very > quickly after the trigger. Later calls into the driver would deadlock > due to the unbalanced state. > > Cc: stable@vger.kernel.org > Fixes: 7c38a551bda1 ("media: cedrus: Add watchdog for job completion") > Signed-off-by: Nicolas Dufresne <nicolas.dufresne@collabora.com> Reviewed-by: Jernej Skrabec <jernej.skrabec@gmail.com> Best regards, Jernej > --- > drivers/staging/media/sunxi/cedrus/cedrus_dec.c | 4 ++-- > 1 file changed, 2 insertions(+), 2 deletions(-) > > diff --git a/drivers/staging/media/sunxi/cedrus/cedrus_dec.c > b/drivers/staging/media/sunxi/cedrus/cedrus_dec.c index > 3b6aa78a2985f..e7f7602a5ab40 100644 > --- a/drivers/staging/media/sunxi/cedrus/cedrus_dec.c > +++ b/drivers/staging/media/sunxi/cedrus/cedrus_dec.c > @@ -106,11 +106,11 @@ void cedrus_device_run(void *priv) > > /* Trigger decoding if setup went well, bail out otherwise. */ > if (!error) { > - dev->dec_ops[ctx->current_codec]->trigger(ctx); > - > /* Start the watchdog timer. */ > schedule_delayed_work(&dev->watchdog_work, > msecs_to_jiffies(2000)); > + > + dev->dec_ops[ctx->current_codec]->trigger(ctx); > } else { > v4l2_m2m_buf_done_and_job_finish(ctx->dev->m2m_dev, > ctx- >fh.m2m_ctx, > -- > 2.37.2
diff --git a/drivers/staging/media/sunxi/cedrus/cedrus_dec.c b/drivers/staging/media/sunxi/cedrus/cedrus_dec.c index 3b6aa78a2985f..e7f7602a5ab40 100644 --- a/drivers/staging/media/sunxi/cedrus/cedrus_dec.c +++ b/drivers/staging/media/sunxi/cedrus/cedrus_dec.c @@ -106,11 +106,11 @@ void cedrus_device_run(void *priv) /* Trigger decoding if setup went well, bail out otherwise. */ if (!error) { - dev->dec_ops[ctx->current_codec]->trigger(ctx); - /* Start the watchdog timer. */ schedule_delayed_work(&dev->watchdog_work, msecs_to_jiffies(2000)); + + dev->dec_ops[ctx->current_codec]->trigger(ctx); } else { v4l2_m2m_buf_done_and_job_finish(ctx->dev->m2m_dev, ctx->fh.m2m_ctx,