linux-kernel - [PATCH 7/7] [mpeg] cx88: don't use atomic

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Date:	Mon, 4 Apr 2011 22:31:15 -0500
From:	Jonathan Nieder <jrnieder@...il.com>
To:	linux-media@...r.kernel.org
Cc:	Huber Andreas <hobrom@...ax.at>,
	Mauro Carvalho Chehab <mchehab@...hat.com>,
	Hans Verkuil <hverkuil@...all.nl>,
	linux-kernel@...r.kernel.org, Ben Hutchings <ben@...adent.org.uk>,
	Steven Toth <stoth@...nellabs.com>
Subject: [PATCH 7/7] [mpeg] cx88: don't use atomic_t for core->users

users is always read or written with core->lock held.  A plain int is
simpler and faster.

Signed-off-by: Jonathan Nieder <jrnieder@...il.com>
---
Thanks for reading.

 drivers/media/video/cx88/cx88-video.c |    5 +++--
 drivers/media/video/cx88/cx88.h       |    2 +-
 2 files changed, 4 insertions(+), 3 deletions(-)

diff --git a/drivers/media/video/cx88/cx88-video.c b/drivers/media/video/cx88/cx88-video.c
index 287a41e..d719d12 100644
--- a/drivers/media/video/cx88/cx88-video.c
+++ b/drivers/media/video/cx88/cx88-video.c
@@ -824,7 +824,7 @@ static int video_open(struct file *file)
 		call_all(core, tuner, s_radio);
 	}
 
-	atomic_inc(&core->users);
+	core->users++;
 	mutex_unlock(&core->lock);
 
 	return 0;
@@ -922,7 +922,8 @@ static int video_release(struct file *file)
 	file->private_data = NULL;
 	kfree(fh);
 
-	if(atomic_dec_and_test(&dev->core->users))
+	dev->core->users--;
+	if (!dev->core->users)
 		call_all(dev->core, core, s_power, 0);
 	mutex_unlock(&dev->core->lock);
 
diff --git a/drivers/media/video/cx88/cx88.h b/drivers/media/video/cx88/cx88.h
index 9e8176e..a399a8b 100644
--- a/drivers/media/video/cx88/cx88.h
+++ b/drivers/media/video/cx88/cx88.h
@@ -389,7 +389,7 @@ struct cx88_core {
 	struct mutex               lock;
 	/* various v4l controls */
 	u32                        freq;
-	atomic_t		   users;
+	int                        users;
 	int                        mpeg_users;
 
 	/* cx88-video needs to access cx8802 for hybrid tuner pll access. */
-- 
1.7.5.rc0

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