lkml.org 
[lkml]   [2010]   [Sep]   [14]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
Patch in this message
/
From
Subject[PATCH 15/18] dvb/bt8xx: kill the big kernel lock
Date
The bt8xx driver only uses the big kernel lock in its dst_ca_ioctl
function and never to serialize against other code, so we can
trivially replace it with a private mutex.

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Cc: linux-media@vger.kernel.org
Cc: Mauro Carvalho Chehab <mchehab@infradead.org>
---
drivers/media/dvb/bt8xx/dst_ca.c | 7 ++++---
1 files changed, 4 insertions(+), 3 deletions(-)
diff --git a/drivers/media/dvb/bt8xx/dst_ca.c b/drivers/media/dvb/bt8xx/dst_ca.c
index cf87051..d75788b 100644
--- a/drivers/media/dvb/bt8xx/dst_ca.c
+++ b/drivers/media/dvb/bt8xx/dst_ca.c
@@ -22,7 +22,7 @@
#include <linux/module.h>
#include <linux/slab.h>
#include <linux/init.h>
-#include <linux/smp_lock.h>
+#include <linux/mutex.h>
#include <linux/string.h>
#include <linux/dvb/ca.h>
#include "dvbdev.h"
@@ -52,6 +52,7 @@
} while(0)


+static DEFINE_MUTEX(dst_ca_mutex);
static unsigned int verbose = 5;
module_param(verbose, int, 0644);
MODULE_PARM_DESC(verbose, "verbose startup messages, default is 1 (yes)");
@@ -564,7 +565,7 @@ static long dst_ca_ioctl(struct file *file, unsigned int cmd, unsigned long ioct
void __user *arg = (void __user *)ioctl_arg;
int result = 0;

- lock_kernel();
+ mutex_lock(&dst_ca_mutex);
dvbdev = file->private_data;
state = (struct dst_state *)dvbdev->priv;
p_ca_message = kmalloc(sizeof (struct ca_msg), GFP_KERNEL);
@@ -652,7 +653,7 @@ static long dst_ca_ioctl(struct file *file, unsigned int cmd, unsigned long ioct
kfree (p_ca_slot_info);
kfree (p_ca_caps);

- unlock_kernel();
+ mutex_unlock(&dst_ca_mutex);
return result;
}

--
1.7.1


\
 
 \ /
  Last update: 2010-09-14 22:01    [from the cache]
©2003-2011 Jasper Spaans