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Commit 438bd525 authored by Stefan Richter's avatar Stefan Richter Committed by Ben Collins
Browse files

[PATCH] ieee1394: dv1394: sem2mutex conversion 



Signed-off-by: Stefan Richter <stefanr@s5r6.in-berlin.de> (not runtime-tested)
Signed-off-by: default avatarBen Collins <bcollins@ubuntu.com>
parent d8831d55

drivers/ieee1394/dv1394-private.h

+3 −3
Original line number Diff line number Diff line
@@ -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;

drivers/ieee1394/dv1394.c

+16 −15
Original line number Diff line number Diff line
@@ -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;