From adfedd216d9f0bc3f5bfa8aab42932301d4edc31 Mon Sep 17 00:00:00 2001 From: Arnd Bergmann Date: Sat, 11 Sep 2010 19:53:25 +0200 Subject: [PATCH] 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: Arnd Bergmann Cc: linux-media@vger.kernel.org Cc: Mauro Carvalho Chehab --- drivers/media/dvb/bt8xx/dst_ca.c | 7 ++++--- 1 file changed, 4 insertions(+), 3 deletions(-) diff --git a/drivers/media/dvb/bt8xx/dst_ca.c b/drivers/media/dvb/bt8xx/dst_ca.c index cf8705162845..d75788b4e22e 100644 --- a/drivers/media/dvb/bt8xx/dst_ca.c +++ b/drivers/media/dvb/bt8xx/dst_ca.c @@ -22,7 +22,7 @@ #include #include #include -#include +#include #include #include #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; }