[media] v4l: kill the BKL

All of the hard problems for BKL removal appear to be solved in the
v4l-dvb/master tree. This removes the BKL from the various open
functions that do not need it, or only use it to protect an
open count.

The zoran driver is nontrivial in this regard, so I introduce
a new mutex that locks both the open/release and the ioctl
functions. Someone with access to the hardware can probably
improve that by using the existing lock in all cases.

Finally, all drivers that still use the locked version of the
ioctl function now get called under a new mutex instead of
the BKL.

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>

1 files changed, 14 insertions, 15 deletions

diff --git a/drivers/media/video/usbvideo/vicam.c b/drivers/media/video/usbvideo/vicam.c
index 5d6fd01f918a..dc17cce2fbb6 100644
--- a/drivers/media/video/usbvideo/vicam.c
+++ b/drivers/media/video/usbvideo/vicam.c
@@ -43,7 +43,6 @@
 #include <linux/vmalloc.h>
 #include <linux/mm.h>
 #include <linux/slab.h>
-#include <linux/smp_lock.h>
 #include <linux/mutex.h>
 #include <linux/firmware.h>
 #include <linux/ihex.h>
@@ -483,29 +482,28 @@ vicam_open(struct file *file)
                 return -EINVAL;
         }
 
-        /* the videodev_lock held above us protects us from
-         * simultaneous opens...for now. we probably shouldn't
-         * rely on this fact forever.
+        /* cam_lock/open_count protects us from simultaneous opens
+         * ... for now. we probably shouldn't rely on this fact forever.
          */
 
-        lock_kernel();
+        mutex_lock(&cam->cam_lock);
         if (cam->open_count > 0) {
                 printk(KERN_INFO
                        "vicam_open called on already opened camera");
-                unlock_kernel();
+                mutex_unlock(&cam->cam_lock);
                 return -EBUSY;
         }
 
         cam->raw_image = kmalloc(VICAM_MAX_READ_SIZE, GFP_KERNEL);
         if (!cam->raw_image) {
-                unlock_kernel();
+                mutex_unlock(&cam->cam_lock);
                 return -ENOMEM;
         }
 
         cam->framebuf = rvmalloc(VICAM_MAX_FRAME_SIZE * VICAM_FRAMES);
         if (!cam->framebuf) {
                 kfree(cam->raw_image);
-                unlock_kernel();
+                mutex_unlock(&cam->cam_lock);
                 return -ENOMEM;
         }
 
@@ -513,10 +511,17 @@ vicam_open(struct file *file)
         if (!cam->cntrlbuf) {
                 kfree(cam->raw_image);
                 rvfree(cam->framebuf, VICAM_MAX_FRAME_SIZE * VICAM_FRAMES);
-                unlock_kernel();
+                mutex_unlock(&cam->cam_lock);
                 return -ENOMEM;
         }
 
+        cam->needsDummyRead = 1;
+        cam->open_count++;
+
+        file->private_data = cam;
+        mutex_unlock(&cam->cam_lock);
+
+
         // First upload firmware, then turn the camera on
 
         if (!cam->is_initialized) {
@@ -527,12 +532,6 @@ vicam_open(struct file *file)
 
         set_camera_power(cam, 1);
 
-        cam->needsDummyRead = 1;
-        cam->open_count++;
-
-        file->private_data = cam;
-        unlock_kernel();
-
         return 0;
 }