From 7b248c767059ce08c8e60043f0718f46223eca51 Mon Sep 17 00:00:00 2001 From: Jernej Skrabec Date: Sun, 9 Oct 2022 20:01:42 +0200 Subject: [PATCH] Allwinner: linux: fix cedrus watchdog race condition --- ...-cedrus--Fix-watchdog-race-condition.patch | 60 +++++++++++++++++++ 1 file changed, 60 insertions(+) create mode 100644 projects/Allwinner/patches/linux/0056-media--cedrus--Fix-watchdog-race-condition.patch diff --git a/projects/Allwinner/patches/linux/0056-media--cedrus--Fix-watchdog-race-condition.patch b/projects/Allwinner/patches/linux/0056-media--cedrus--Fix-watchdog-race-condition.patch new file mode 100644 index 0000000000..299bdf199a --- /dev/null +++ b/projects/Allwinner/patches/linux/0056-media--cedrus--Fix-watchdog-race-condition.patch @@ -0,0 +1,60 @@ +From: Nicolas Dufresne +To: linux-media@vger.kernel.org, Maxime Ripard , + Paul Kocialkowski , + Mauro Carvalho Chehab , + Greg Kroah-Hartman , + Chen-Yu Tsai , + Jernej Skrabec , + Samuel Holland , + Ezequiel Garcia , + Hans Verkuil +Cc: kernel@collabora.com, + Nicolas Dufresne , + 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 + +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 +Reviewed-by: Paul Kocialkowski +Reviewed-by: Jernej Skrabec +--- + 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 +@@ -92,10 +192,10 @@ void cedrus_device_run(void *priv) + if (src_req) + v4l2_ctrl_request_complete(src_req, &ctx->hdl); + +- 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); + } +