[PATCH] ieee1394: dv1394: sem2mutex conversion

Signed-off-by: Stefan Richter <stefanr@s5r6.in-berlin.de> (not runtime-tested)
Signed-off-by: Ben Collins <bcollins@ubuntu.com>

2 files changed, 19 insertions, 18 deletions

diff --git a/drivers/ieee1394/dv1394-private.h b/drivers/ieee1394/dv1394-private.h
index 80b5ac7fe383..7d1d2845b420 100644
--- a/drivers/ieee1394/dv1394-private.h
+++ b/drivers/ieee1394/dv1394-private.h
@@ -460,7 +460,7 @@ struct video_card {
         int dma_running;
 
         /*
-          3) the sleeping semaphore 'sem' - this is used from process context only,
+          3) the sleeping mutex 'mtx' - this is used from process context only,
           to serialize various operations on the video_card. Even though only one
           open() is allowed, we still need to prevent multiple threads of execution
           from entering calls like read, write, ioctl, etc.
@@ -468,9 +468,9 @@ struct video_card {
           I honestly can't think of a good reason to use dv1394 from several threads
           at once, but we need to serialize anyway to prevent oopses =).
 
-          NOTE: if you need both spinlock and sem, take sem first to avoid deadlock!
+          NOTE: if you need both spinlock and mtx, take mtx first to avoid deadlock!
          */
-        struct semaphore sem;
+        struct mutex mtx;
 
         /* people waiting for buffer space, please form a line here... */
         wait_queue_head_t waitq;
diff --git a/drivers/ieee1394/dv1394.c b/drivers/ieee1394/dv1394.c
index bdc50f25fb42..6e71d68b1099 100644
--- a/drivers/ieee1394/dv1394.c
+++ b/drivers/ieee1394/dv1394.c
@@ -95,6 +95,7 @@
 #include <linux/fs.h>
 #include <linux/poll.h>
 #include <linux/smp_lock.h>
+#include <linux/mutex.h>
 #include <linux/bitops.h>
 #include <asm/byteorder.h>
 #include <asm/atomic.h>
@@ -247,7 +248,7 @@ static void frame_delete(struct frame *f)
 
    Frame_prepare() must be called OUTSIDE the video->spinlock.
    However, frame_prepare() must still be serialized, so
-   it should be called WITH the video->sem taken.
+   it should be called WITH the video->mtx taken.
  */
 
 static void frame_prepare(struct video_card *video, unsigned int this_frame)
@@ -1271,7 +1272,7 @@ static int dv1394_mmap(struct file *file, struct vm_area_struct *vma)
         int retval = -EINVAL;
 
         /* serialize mmap */
-        down(&video->sem);
+        mutex_lock(&video->mtx);
 
         if ( ! video_card_initialized(video) ) {
                 retval = do_dv1394_init_default(video);
@@ -1281,7 +1282,7 @@ static int dv1394_mmap(struct file *file, struct vm_area_struct *vma)
 
         retval = dma_region_mmap(&video->dv_buf, file, vma);
 out:
-        up(&video->sem);
+        mutex_unlock(&video->mtx);
         return retval;
 }
 
@@ -1337,17 +1338,17 @@ static ssize_t dv1394_write(struct file *file, const char __user *buffer, size_t
 
         /* serialize this to prevent multi-threaded mayhem */
         if (file->f_flags & O_NONBLOCK) {
-                if (down_trylock(&video->sem))
+                if (!mutex_trylock(&video->mtx))
                         return -EAGAIN;
         } else {
-                if (down_interruptible(&video->sem))
+                if (mutex_lock_interruptible(&video->mtx))
                         return -ERESTARTSYS;
         }
 
         if ( !video_card_initialized(video) ) {
                 ret = do_dv1394_init_default(video);
                 if (ret) {
-                        up(&video->sem);
+                        mutex_unlock(&video->mtx);
                         return ret;
                 }
         }
@@ -1418,7 +1419,7 @@ static ssize_t dv1394_write(struct file *file, const char __user *buffer, size_t
 
         remove_wait_queue(&video->waitq, &wait);
         set_current_state(TASK_RUNNING);
-        up(&video->sem);
+        mutex_unlock(&video->mtx);
         return ret;
 }
 
@@ -1434,17 +1435,17 @@ static ssize_t dv1394_read(struct file *file,  char __user *buffer, size_t count
 
         /* serialize this to prevent multi-threaded mayhem */
         if (file->f_flags & O_NONBLOCK) {
-                if (down_trylock(&video->sem))
+                if (!mutex_trylock(&video->mtx))
                         return -EAGAIN;
         } else {
-                if (down_interruptible(&video->sem))
+                if (mutex_lock_interruptible(&video->mtx))
                         return -ERESTARTSYS;
         }
 
         if ( !video_card_initialized(video) ) {
                 ret = do_dv1394_init_default(video);
                 if (ret) {
-                        up(&video->sem);
+                        mutex_unlock(&video->mtx);
                         return ret;
                 }
                 video->continuity_counter = -1;
@@ -1526,7 +1527,7 @@ static ssize_t dv1394_read(struct file *file,  char __user *buffer, size_t count
 
         remove_wait_queue(&video->waitq, &wait);
         set_current_state(TASK_RUNNING);
-        up(&video->sem);
+        mutex_unlock(&video->mtx);
         return ret;
 }
 
@@ -1547,12 +1548,12 @@ static long dv1394_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
 
         /* serialize this to prevent multi-threaded mayhem */
         if (file->f_flags & O_NONBLOCK) {
-                if (down_trylock(&video->sem)) {
+                if (!mutex_trylock(&video->mtx)) {
                         unlock_kernel();
                         return -EAGAIN;
                 }
         } else {
-                if (down_interruptible(&video->sem)) {
+                if (mutex_lock_interruptible(&video->mtx)) {
                         unlock_kernel();
                         return -ERESTARTSYS;
                 }
@@ -1778,7 +1779,7 @@ static long dv1394_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
         }
 
  out:
-        up(&video->sem);
+        mutex_unlock(&video->mtx);
         unlock_kernel();
         return ret;
 }
@@ -2253,7 +2254,7 @@ static int dv1394_init(struct ti_ohci *ohci, enum pal_or_ntsc format, enum modes
         clear_bit(0, &video->open);
         spin_lock_init(&video->spinlock);
         video->dma_running = 0;
-        init_MUTEX(&video->sem);
+        mutex_init(&video->mtx);
         init_waitqueue_head(&video->waitq);
         video->fasync = NULL;