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From: Dan Carpenter <dan.carpenter@oracle.com>
To: Mauro Carvalho Chehab <m.chehab@samsung.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
	Laurent Pinchart <laurent.pinchart@ideasonboard.com>,
	Hans Verkuil <hans.verkuil@cisco.com>,
	Sergio Aguirre <sergio.a.aguirre@gmail.com>,
	linux-media@vger.kernel.org, devel@driverdev.osuosl.org,
	kernel-janitors@vger.kernel.org
Subject: [patch v2] [media] v4l: omap4iss: Restore irq flags correctly in omap4iss_video_buffer_next()
Date: Wed, 18 Dec 2013 07:29:24 +0000	[thread overview]
Message-ID: <20131216150612.GA15506@elgon.mountain> (raw)

The spin_lock_irqsave() macro is not nestable.  The second call will
overwrite the first record of "flags" so the IRQs will not be enabled
correctly at the end of the function.

In the current code, this function is always called from the IRQ handler
so everything works fine and this fix doesn't change anything.

Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
---
v2:  Updated the change log

diff --git a/drivers/staging/media/omap4iss/iss_video.c b/drivers/staging/media/omap4iss/iss_video.c
index 766491e6a8d0..c9b71c750b15 100644
--- a/drivers/staging/media/omap4iss/iss_video.c
+++ b/drivers/staging/media/omap4iss/iss_video.c
@@ -451,9 +451,9 @@ struct iss_buffer *omap4iss_video_buffer_next(struct iss_video *video)
 	}
 
 	if (video->type = V4L2_BUF_TYPE_VIDEO_CAPTURE && pipe->input != NULL) {
-		spin_lock_irqsave(&pipe->lock, flags);
+		spin_lock(&pipe->lock);
 		pipe->state &= ~ISS_PIPELINE_STREAM;
-		spin_unlock_irqrestore(&pipe->lock, flags);
+		spin_unlock(&pipe->lock);
 	}
 
 	buf = list_first_entry(&video->dmaqueue, struct iss_buffer,
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WARNING: multiple messages have this Message-ID (diff)
From: Dan Carpenter <dan.carpenter@oracle.com>
To: Mauro Carvalho Chehab <m.chehab@samsung.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
	Laurent Pinchart <laurent.pinchart@ideasonboard.com>,
	Hans Verkuil <hans.verkuil@cisco.com>,
	Sergio Aguirre <sergio.a.aguirre@gmail.com>,
	linux-media@vger.kernel.org, devel@driverdev.osuosl.org,
	kernel-janitors@vger.kernel.org
Subject: [media] v4l: omap4iss: Restore irq flags correctly in omap4iss_video_buffer_next()
Date: Mon, 16 Dec 2013 18:06:12 +0300	[thread overview]
Message-ID: <20131216150612.GA15506@elgon.mountain> (raw)

The spin_lock_irqsave() macro is not nestable.  The second call will
overwrite the first record of "flags" so the IRQs will not be enabled
correctly at the end of the function.

I haven't looked at all the callers but it could be that this function
is always called with interrupts disabled and the bug doesn't cause
problems in real life.

Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>

diff --git a/drivers/staging/media/omap4iss/iss_video.c b/drivers/staging/media/omap4iss/iss_video.c
index 766491e6a8d0..c9b71c750b15 100644
--- a/drivers/staging/media/omap4iss/iss_video.c
+++ b/drivers/staging/media/omap4iss/iss_video.c
@@ -451,9 +451,9 @@ struct iss_buffer *omap4iss_video_buffer_next(struct iss_video *video)
 	}
 
 	if (video->type == V4L2_BUF_TYPE_VIDEO_CAPTURE && pipe->input != NULL) {
-		spin_lock_irqsave(&pipe->lock, flags);
+		spin_lock(&pipe->lock);
 		pipe->state &= ~ISS_PIPELINE_STREAM;
-		spin_unlock_irqrestore(&pipe->lock, flags);
+		spin_unlock(&pipe->lock);
 	}
 
 	buf = list_first_entry(&video->dmaqueue, struct iss_buffer,

             reply	other threads:[~2013-12-18  7:29 UTC|newest]

Thread overview: 6+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2013-12-16 15:06 Dan Carpenter [this message]
2013-12-18  7:29 ` [patch v2] [media] v4l: omap4iss: Restore irq flags correctly in omap4iss_video_buffer_next() Dan Carpenter
2013-12-17 17:28 ` Laurent Pinchart
2013-12-17 17:28   ` Laurent Pinchart
2013-12-19  1:03 ` [patch v2] " Laurent Pinchart
2013-12-19  1:03   ` Laurent Pinchart

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