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Commit adfedd21 authored by Arnd Bergmann's avatar Arnd Bergmann
Browse files

dvb/bt8xx: kill the big kernel lock 



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: default avatarArnd Bergmann <arnd@arndb.de>
Cc: linux-media@vger.kernel.org
Cc: Mauro Carvalho Chehab <mchehab@infradead.org>
parent efbec1cd

drivers/media/dvb/bt8xx/dst_ca.c

+4 −3
Original line number Original line Diff line number Diff line
@@ -22,7 +22,7 @@ 
#include <linux/module.h>

#include <linux/module.h>

#include <linux/slab.h>

#include <linux/slab.h>

#include <linux/init.h>

#include <linux/init.h>

#include <linux/smp_lock.h>

#include <linux/mutex.h>

#include <linux/string.h>

#include <linux/string.h>

#include <linux/dvb/ca.h>

#include <linux/dvb/ca.h>

#include "dvbdev.h"

#include "dvbdev.h"
@@ -52,6 +52,7 @@ 
} while(0)

} while(0)









static DEFINE_MUTEX(dst_ca_mutex);

static unsigned int verbose = 5;

static unsigned int verbose = 5;

module_param(verbose, int, 0644);

module_param(verbose, int, 0644);

MODULE_PARM_DESC(verbose, "verbose startup messages, default is 1 (yes)");

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;

	void __user *arg = (void __user *)ioctl_arg;

	int result = 0;

	int result = 0;





	lock_kernel();

	mutex_lock(&dst_ca_mutex);

	dvbdev = file->private_data;

	dvbdev = file->private_data;

	state = (struct dst_state *)dvbdev->priv;

	state = (struct dst_state *)dvbdev->priv;

	p_ca_message = kmalloc(sizeof (struct ca_msg), GFP_KERNEL);

	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_slot_info);

	kfree (p_ca_caps);

	kfree (p_ca_caps);





	unlock_kernel();

	mutex_unlock(&dst_ca_mutex);

	return result;

	return result;

}

}