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From: Jonathan Nieder <jrnieder@gmail.com>
To: linux-media@vger.kernel.org
Cc: Huber Andreas <hobrom@corax.at>,
	Mauro Carvalho Chehab <mchehab@redhat.com>,
	Hans Verkuil <hverkuil@xs4all.nl>,
	linux-kernel@vger.kernel.org, Ben Hutchings <ben@decadent.org.uk>,
	Steven Toth <stoth@kernellabs.com>
Subject: [PATCH 7/7] [mpeg] cx88: don't use atomic_t for core->users
Date: Mon, 4 Apr 2011 22:31:15 -0500	[thread overview]
Message-ID: <20110405033114.GH4498@elie> (raw)
In-Reply-To: <20110405032014.GA4498@elie>

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

Signed-off-by: Jonathan Nieder <jrnieder@gmail.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


  parent reply	other threads:[~2011-04-05  3:31 UTC|newest]

Thread overview: 22+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
     [not found] <20110327150610.4029.95961.reportbug@xen.corax.at>
2011-03-27 15:28 ` [linux-dvb] cx88-blackbird broken (since 2.6.37) Jonathan Nieder
2011-04-02  9:38   ` [RFC/PATCH 0/3] locking fixes for cx88 Jonathan Nieder
2011-04-02  9:41     ` [PATCH 1/3] [media] cx88: protect per-device driver list with device lock Jonathan Nieder
2011-04-02  9:41     ` [PATCH 2/3] [media] cx88: fix locking of sub-driver operations Jonathan Nieder
2011-04-02  9:44     ` [PATCH 3/3] [media] cx88: use a mutex to protect cx8802_devlist Jonathan Nieder
     [not found]       ` <4D971B8D.4040305@corax.at>
2011-04-02 19:29         ` Jonathan Nieder
2011-04-02 20:13           ` Andreas Huber
2011-04-04  2:12             ` Andreas Huber
2011-04-05  1:16               ` Jonathan Nieder
2011-04-02 14:05     ` [RFC/PATCH 0/3] locking fixes for cx88 Andreas Huber
2011-04-02 15:19     ` Ben Hutchings
2011-04-02 18:30       ` Jonathan Nieder
2011-04-05  3:20     ` [RFC/PATCH v2 0/7] " Jonathan Nieder
2011-04-05  3:22       ` [PATCH 1/7] [media] cx88: protect per-device driver list with device lock Jonathan Nieder
2011-04-05  3:25       ` [PATCH 2/7] [media] cx88: fix locking of sub-driver operations Jonathan Nieder
2011-04-05  3:27       ` [PATCH 3/7] [media] cx88: hold device lock during sub-driver initialization Jonathan Nieder
2011-04-05  3:27       ` [PATCH 4/7] [media] cx88: use a mutex to protect cx8802_devlist Jonathan Nieder
2011-04-05  3:29       ` [PATCH 5/7] [media] cx88: gracefully reject attempts to use unregistered cx88-blackbird driver Jonathan Nieder
2011-04-05  3:30       ` [PATCH 6/7] [media] cx88: don't use atomic_t for core->mpeg_users Jonathan Nieder
2011-04-05  3:31       ` Jonathan Nieder [this message]
2011-04-05  3:41         ` [PATCH 7/7] [mpeg] cx88: don't use atomic_t for core->users Jonathan Nieder
2011-04-05 18:17       ` [RFC/PATCH v2 0/7] locking fixes for cx88 Jonathan Nieder

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