[Patch v2 1/1] media: am437x-vpfe: Fix a race condition during release

Path	csiph.com!aioe.org!bofh.it!news.nic.it!robomod
From	Benoit Parrot <bparrot@ti.com>
Newsgroups	linux.kernel
Subject	[Patch v2 1/1] media: am437x-vpfe: Fix a race condition during release
Date	Mon, 29 Jun 2015 23:00:02 +0200
Message-ID	<pGOjM-5WS-9@gated-at.bofh.it> (permalink)
X-Original-To	Hans Verkuil <hverkuil@xs4all.nl>
X-Mailer	git-send-email 1.8.5.1
MIME-Version	1.0
Content-Type	text/plain
Sender	robomod@news.nic.it
List-ID	<linux-kernel.vger.kernel.org>
X-Mailing-List	linux-kernel@vger.kernel.org
Approved	robomod@news.nic.it
Lines	50
Organization	linux.* mail to news gateway
X-Original-Cc	Prabhakar Lad <prabhakar.csengg@gmail.com>, <linux-media@vger.kernel.org>, <linux-kernel@vger.kernel.org>, Benoit Parrot <bparrot@ti.com>, <stable@vger.kernel.org>
X-Original-Date	Mon, 29 Jun 2015 15:51:10 -0500
X-Original-Message-ID	<1435611070-3239-1-git-send-email-bparrot@ti.com>
X-Original-Sender	linux-kernel-owner@vger.kernel.org
Xref	aioe.org linux.kernel:1174103

Show key headers only | View raw

There was a race condition where during cleanup/release operation
on-going streaming would cause a kernel panic because the hardware
module was disabled prematurely with IRQ still pending.

Fixes: 417d2e507ed [media] media: platform: add VPFE capture driver support for AM437X
Cc: <stable@vger.kernel.org> # v4.0+
Signed-off-by: Benoit Parrot <bparrot@ti.com>
---
Changes from v1:
- Added stable reference

 drivers/media/platform/am437x/am437x-vpfe.c | 11 +++++++++--
 1 file changed, 9 insertions(+), 2 deletions(-)

diff --git a/drivers/media/platform/am437x/am437x-vpfe.c b/drivers/media/platform/am437x/am437x-vpfe.c
index a30cc2f..eb25c43 100644
--- a/drivers/media/platform/am437x/am437x-vpfe.c
+++ b/drivers/media/platform/am437x/am437x-vpfe.c
@@ -1185,14 +1185,21 @@ static int vpfe_initialize_device(struct vpfe_device *vpfe)
 static int vpfe_release(struct file *file)
 {
 	struct vpfe_device *vpfe = video_drvdata(file);
+	bool fh_singular = v4l2_fh_is_singular_file(file);
 	int ret;
 
 	mutex_lock(&vpfe->lock);
 
-	if (v4l2_fh_is_singular_file(file))
-		vpfe_ccdc_close(&vpfe->ccdc, vpfe->pdev);
+	/* the release helper will cleanup any on-going streaming */
 	ret = _vb2_fop_release(file, NULL);
 
+	/*
+	 * If this was the last open file.
+	 * Then de-initialize hw module.
+	 */
+	if (fh_singular)
+		vpfe_ccdc_close(&vpfe->ccdc, vpfe->pdev);
+
 	mutex_unlock(&vpfe->lock);
 
 	return ret;
-- 
1.8.5.1

--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/

Back to linux.kernel | Previous | Next | Find similar | Unroll thread

Thread

[Patch v2 1/1] media: am437x-vpfe: Fix a race condition during release Benoit Parrot <bparrot@ti.com> - 2015-06-29 23:00 +0200

csiph-web