diff mbox

[V2] poll method lose race condition

Message ID 1243821904.3499.5.camel@myhost (mailing list archive)
State Changes Requested
Headers show

Commit Message

Figo.zhang June 1, 2009, 2:05 a.m. UTC
bttv-driver.c,cx23885-video.c,cx88-video.c: poll method lose race condition for capture video.

 In v2, use the clear logic.Thanks to Trent Piepho's help.

Signed-off-by: Figo.zhang <figo1802@gmail.com>
---
 drivers/media/video/bt8xx/bttv-driver.c     |   20 ++++++++++++--------
 drivers/media/video/cx23885/cx23885-video.c |   15 +++++++++++----
 drivers/media/video/cx88/cx88-video.c       |   15 +++++++++++----
 3 files changed, 34 insertions(+), 16 deletions(-)



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Comments

Figo.zhang June 15, 2009, 1:28 p.m. UTC | #1
hi Mauro,

 is it ok for this v2?

Best Regards,
Figo.zhang

> 2009/6/1 Figo.zhang <figo1802@gmail.com>
>          bttv-driver.c,cx23885-video.c,cx88-video.c: poll method lose
>         race condition for capture video.
>         
>          In v2, use the clear logic.Thanks to Trent Piepho's help.
>         
>         Signed-off-by: Figo.zhang <figo1802@gmail.com>
>         ---
>          drivers/media/video/bt8xx/bttv-driver.c     |   20
>         ++++++++++++--------
>          drivers/media/video/cx23885/cx23885-video.c |   15
>         +++++++++++----
>          drivers/media/video/cx88/cx88-video.c       |   15
>         +++++++++++----
>          3 files changed, 34 insertions(+), 16 deletions(-)
>         
>         diff --git a/drivers/media/video/bt8xx/bttv-driver.c
>         b/drivers/media/video/bt8xx/bttv-driver.c
>         index 23b7499..8d20528 100644
>         --- a/drivers/media/video/bt8xx/bttv-driver.c
>         +++ b/drivers/media/video/bt8xx/bttv-driver.c
>         @@ -3152,6 +3152,7 @@ static unsigned int bttv_poll(struct
>         file *file, poll_table *wait)
>                struct bttv_fh *fh = file->private_data;
>                struct bttv_buffer *buf;
>                enum v4l2_field field;
>         +       unsigned int rc = POLLERR;
>         
>                if (V4L2_BUF_TYPE_VBI_CAPTURE == fh->type) {
>                        if (!
>         check_alloc_btres(fh->btv,fh,RESOURCE_VBI))
>         @@ -3160,9 +3161,10 @@ static unsigned int bttv_poll(struct
>         file *file, poll_table *wait)
>                }
>         
>                if (check_btres(fh,RESOURCE_VIDEO_STREAM)) {
>         +               mutex_lock(&fh->cap.vb_lock);
>                        /* streaming capture */
>                        if (list_empty(&fh->cap.stream))
>         -                       return POLLERR;
>         +                       return done;
>                        buf = list_entry(fh->cap.stream.next,struct
>         bttv_buffer,vb.stream);
>                } else {
>                        /* read() capture */
>         @@ -3170,16 +3172,16 @@ static unsigned int bttv_poll(struct
>         file *file, poll_table *wait)
>                        if (NULL == fh->cap.read_buf) {
>                                /* need to capture a new frame */
>                                if
>         (locked_btres(fh->btv,RESOURCE_VIDEO_STREAM))
>         -                               goto err;
>         +                               goto done;
>                                fh->cap.read_buf =
>         videobuf_sg_alloc(fh->cap.msize);
>                                if (NULL == fh->cap.read_buf)
>         -                               goto err;
>         +                               goto done;
>                                fh->cap.read_buf->memory =
>         V4L2_MEMORY_USERPTR;
>                                field = videobuf_next_field(&fh->cap);
>                                if (0 !=
>         fh->cap.ops->buf_prepare(&fh->cap,fh->cap.read_buf,field)) {
>                                        kfree (fh->cap.read_buf);
>                                        fh->cap.read_buf = NULL;
>         -                               goto err;
>         +                               goto done;
>                                }
>         
>          fh->cap.ops->buf_queue(&fh->cap,fh->cap.read_buf);
>                                fh->cap.read_off = 0;
>         @@ -3191,11 +3193,13 @@ static unsigned int bttv_poll(struct
>         file *file, poll_table *wait)
>                poll_wait(file, &buf->vb.done, wait);
>                if (buf->vb.state == VIDEOBUF_DONE ||
>                    buf->vb.state == VIDEOBUF_ERROR)
>         -               return POLLIN|POLLRDNORM;
>         -       return 0;
>         -err:
>         +               rc =  POLLIN|POLLRDNORM;
>         +       else
>         +               rc = 0;
>         +
>         +done:
>                mutex_unlock(&fh->cap.vb_lock);
>         -       return POLLERR;
>         +       return rc;
>          }
>         
>          static int bttv_open(struct file *file)
>         diff --git a/drivers/media/video/cx23885/cx23885-video.c
>         b/drivers/media/video/cx23885/cx23885-video.c
>         index 68068c6..f542493 100644
>         --- a/drivers/media/video/cx23885/cx23885-video.c
>         +++ b/drivers/media/video/cx23885/cx23885-video.c
>         @@ -796,6 +796,7 @@ static unsigned int video_poll(struct file
>         *file,
>          {
>                struct cx23885_fh *fh = file->private_data;
>                struct cx23885_buffer *buf;
>         +       unsigned int rc = POLLERR;
>         
>                if (V4L2_BUF_TYPE_VBI_CAPTURE == fh->type) {
>                        if (!res_get(fh->dev, fh, RESOURCE_VBI))
>         @@ -803,23 +804,29 @@ static unsigned int video_poll(struct
>         file *file,
>                        return videobuf_poll_stream(file, &fh->vbiq,
>         wait);
>                }
>         
>         +       mutex_lock(&fh->vidq.vb_lock);
>                if (res_check(fh, RESOURCE_VIDEO)) {
>                        /* streaming capture */
>                        if (list_empty(&fh->vidq.stream))
>         -                       return POLLERR;
>         +                       goto done;
>                        buf = list_entry(fh->vidq.stream.next,
>                                struct cx23885_buffer, vb.stream);
>                } else {
>                        /* read() capture */
>                        buf = (struct cx23885_buffer
>         *)fh->vidq.read_buf;
>                        if (NULL == buf)
>         -                       return POLLERR;
>         +                       goto done;
>                }
>                poll_wait(file, &buf->vb.done, wait);
>                if (buf->vb.state == VIDEOBUF_DONE ||
>                    buf->vb.state == VIDEOBUF_ERROR)
>         -               return POLLIN|POLLRDNORM;
>         -       return 0;
>         +               rc =  POLLIN|POLLRDNORM;
>         +       else
>         +               rc = 0;
>         +
>         +done:
>         +       mutex_unlock(&fh->vidq.vb_lock);
>         +       return rc;
>          }
>         
>          static int video_release(struct file *file)
>         diff --git a/drivers/media/video/cx88/cx88-video.c
>         b/drivers/media/video/cx88/cx88-video.c
>         index b993d42..b1ca54b 100644
>         --- a/drivers/media/video/cx88/cx88-video.c
>         +++ b/drivers/media/video/cx88/cx88-video.c
>         @@ -869,6 +869,7 @@ video_poll(struct file *file, struct
>         poll_table_struct *wait)
>          {
>                struct cx8800_fh *fh = file->private_data;
>                struct cx88_buffer *buf;
>         +       unsigned int rc = POLLERR;
>         
>                if (V4L2_BUF_TYPE_VBI_CAPTURE == fh->type) {
>                        if (!res_get(fh->dev,fh,RESOURCE_VBI))
>         @@ -876,22 +877,28 @@ video_poll(struct file *file, struct
>         poll_table_struct *wait)
>                        return videobuf_poll_stream(file, &fh->vbiq,
>         wait);
>                }
>         
>         +       mutex_lock(&fh->vidq.vb_lock);
>                if (res_check(fh,RESOURCE_VIDEO)) {
>                        /* streaming capture */
>                        if (list_empty(&fh->vidq.stream))
>         -                       return POLLERR;
>         +                       goto done;
>                        buf = list_entry(fh->vidq.stream.next,struct
>         cx88_buffer,vb.stream);
>                } else {
>                        /* read() capture */
>                        buf = (struct cx88_buffer*)fh->vidq.read_buf;
>                        if (NULL == buf)
>         -                       return POLLERR;
>         +                       goto done;
>                }
>                poll_wait(file, &buf->vb.done, wait);
>                if (buf->vb.state == VIDEOBUF_DONE ||
>                    buf->vb.state == VIDEOBUF_ERROR)
>         -               return POLLIN|POLLRDNORM;
>         -       return 0;
>         +               rc =  POLLIN|POLLRDNORM;
>         +       else
>         +               rc = 0;
>         +
>         +done:
>         +       mutex_unlock(&fh->vidq.vb_lock);
>         +       return rc;
>          }
>         
>          static int video_release(struct file *file)
>         
>         
> 

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Mauro Carvalho Chehab June 16, 2009, 3:51 p.m. UTC | #2
Em Mon, 01 Jun 2009 10:05:04 +0800
"Figo.zhang" <figo1802@gmail.com> escreveu:

>  bttv-driver.c,cx23885-video.c,cx88-video.c: poll method lose race condition for capture video.
> 
>  In v2, use the clear logic.Thanks to Trent Piepho's help.
> 
> Signed-off-by: Figo.zhang <figo1802@gmail.com>
> ---
>  drivers/media/video/bt8xx/bttv-driver.c     |   20 ++++++++++++--------
>  drivers/media/video/cx23885/cx23885-video.c |   15 +++++++++++----
>  drivers/media/video/cx88/cx88-video.c       |   15 +++++++++++----
>  3 files changed, 34 insertions(+), 16 deletions(-)
> 
> diff --git a/drivers/media/video/bt8xx/bttv-driver.c b/drivers/media/video/bt8xx/bttv-driver.c
> index 23b7499..8d20528 100644
> --- a/drivers/media/video/bt8xx/bttv-driver.c
> +++ b/drivers/media/video/bt8xx/bttv-driver.c
> @@ -3152,6 +3152,7 @@ static unsigned int bttv_poll(struct file *file, poll_table *wait)
>  	struct bttv_fh *fh = file->private_data;
>  	struct bttv_buffer *buf;
>  	enum v4l2_field field;
> +	unsigned int rc = POLLERR;
>  
>  	if (V4L2_BUF_TYPE_VBI_CAPTURE == fh->type) {
>  		if (!check_alloc_btres(fh->btv,fh,RESOURCE_VBI))
> @@ -3160,9 +3161,10 @@ static unsigned int bttv_poll(struct file *file, poll_table *wait)
>  	}
>  
>  	if (check_btres(fh,RESOURCE_VIDEO_STREAM)) {
> +		mutex_lock(&fh->cap.vb_lock);
>  		/* streaming capture */
>  		if (list_empty(&fh->cap.stream))
> -			return POLLERR;
> +			return done;

Here, you're keeping the mutex locked. Maybe you wanted to do a "goto done" ?

>  		buf = list_entry(fh->cap.stream.next,struct bttv_buffer,vb.stream);
>  	} else {
>  		/* read() capture */
> @@ -3170,16 +3172,16 @@ static unsigned int bttv_poll(struct file *file, poll_table *wait)
>  		if (NULL == fh->cap.read_buf) {
>  			/* need to capture a new frame */
>  			if (locked_btres(fh->btv,RESOURCE_VIDEO_STREAM))
> -				goto err;
> +				goto done;
>  			fh->cap.read_buf = videobuf_sg_alloc(fh->cap.msize);
>  			if (NULL == fh->cap.read_buf)
> -				goto err;
> +				goto done;
>  			fh->cap.read_buf->memory = V4L2_MEMORY_USERPTR;
>  			field = videobuf_next_field(&fh->cap);
>  			if (0 != fh->cap.ops->buf_prepare(&fh->cap,fh->cap.read_buf,field)) {
>  				kfree (fh->cap.read_buf);
>  				fh->cap.read_buf = NULL;
> -				goto err;
> +				goto done;
>  			}
>  			fh->cap.ops->buf_queue(&fh->cap,fh->cap.read_buf);
>  			fh->cap.read_off = 0;
> @@ -3191,11 +3193,13 @@ static unsigned int bttv_poll(struct file *file, poll_table *wait)
>  	poll_wait(file, &buf->vb.done, wait);
>  	if (buf->vb.state == VIDEOBUF_DONE ||
>  	    buf->vb.state == VIDEOBUF_ERROR)
> -		return POLLIN|POLLRDNORM;
> -	return 0;
> -err:
> +		rc =  POLLIN|POLLRDNORM;
> +	else 
> +		rc = 0;
> +	
> +done:
>  	mutex_unlock(&fh->cap.vb_lock);
> -	return POLLERR;
> +	return rc;
>  }
>  
>  static int bttv_open(struct file *file)
> diff --git a/drivers/media/video/cx23885/cx23885-video.c b/drivers/media/video/cx23885/cx23885-video.c
> index 68068c6..f542493 100644
> --- a/drivers/media/video/cx23885/cx23885-video.c
> +++ b/drivers/media/video/cx23885/cx23885-video.c
> @@ -796,6 +796,7 @@ static unsigned int video_poll(struct file *file,
>  {
>  	struct cx23885_fh *fh = file->private_data;
>  	struct cx23885_buffer *buf;
> +	unsigned int rc = POLLERR;
>  
>  	if (V4L2_BUF_TYPE_VBI_CAPTURE == fh->type) {
>  		if (!res_get(fh->dev, fh, RESOURCE_VBI))
> @@ -803,23 +804,29 @@ static unsigned int video_poll(struct file *file,
>  		return videobuf_poll_stream(file, &fh->vbiq, wait);
>  	}
>  
> +	mutex_lock(&fh->vidq.vb_lock);
>  	if (res_check(fh, RESOURCE_VIDEO)) {
>  		/* streaming capture */
>  		if (list_empty(&fh->vidq.stream))
> -			return POLLERR;
> +			goto done;
>  		buf = list_entry(fh->vidq.stream.next,
>  			struct cx23885_buffer, vb.stream);
>  	} else {
>  		/* read() capture */
>  		buf = (struct cx23885_buffer *)fh->vidq.read_buf;
>  		if (NULL == buf)
> -			return POLLERR;
> +			goto done;
>  	}
>  	poll_wait(file, &buf->vb.done, wait);
>  	if (buf->vb.state == VIDEOBUF_DONE ||
>  	    buf->vb.state == VIDEOBUF_ERROR)
> -		return POLLIN|POLLRDNORM;
> -	return 0;
> +		rc =  POLLIN|POLLRDNORM;
> +	else
> +		rc = 0;
> +
> +done:
> +	mutex_unlock(&fh->vidq.vb_lock);
> +	return rc;
>  }
>  
>  static int video_release(struct file *file)
> diff --git a/drivers/media/video/cx88/cx88-video.c b/drivers/media/video/cx88/cx88-video.c
> index b993d42..b1ca54b 100644
> --- a/drivers/media/video/cx88/cx88-video.c
> +++ b/drivers/media/video/cx88/cx88-video.c
> @@ -869,6 +869,7 @@ video_poll(struct file *file, struct poll_table_struct *wait)
>  {
>  	struct cx8800_fh *fh = file->private_data;
>  	struct cx88_buffer *buf;
> +	unsigned int rc = POLLERR;
>  
>  	if (V4L2_BUF_TYPE_VBI_CAPTURE == fh->type) {
>  		if (!res_get(fh->dev,fh,RESOURCE_VBI))
> @@ -876,22 +877,28 @@ video_poll(struct file *file, struct poll_table_struct *wait)
>  		return videobuf_poll_stream(file, &fh->vbiq, wait);
>  	}
>  
> +	mutex_lock(&fh->vidq.vb_lock);
>  	if (res_check(fh,RESOURCE_VIDEO)) {
>  		/* streaming capture */
>  		if (list_empty(&fh->vidq.stream))
> -			return POLLERR;
> +			goto done;
>  		buf = list_entry(fh->vidq.stream.next,struct cx88_buffer,vb.stream);
>  	} else {
>  		/* read() capture */
>  		buf = (struct cx88_buffer*)fh->vidq.read_buf;
>  		if (NULL == buf)
> -			return POLLERR;
> +			goto done;
>  	}
>  	poll_wait(file, &buf->vb.done, wait);
>  	if (buf->vb.state == VIDEOBUF_DONE ||
>  	    buf->vb.state == VIDEOBUF_ERROR)
> -		return POLLIN|POLLRDNORM;
> -	return 0;
> +		rc =  POLLIN|POLLRDNORM;
> +	else
> +		rc = 0;
> +
> +done:
> +	mutex_unlock(&fh->vidq.vb_lock);
> +	return rc;
>  }
>  
>  static int video_release(struct file *file)
> 
> 
> --
> To unsubscribe from this list: send the line "unsubscribe linux-media" in
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diff mbox

Patch

diff --git a/drivers/media/video/bt8xx/bttv-driver.c b/drivers/media/video/bt8xx/bttv-driver.c
index 23b7499..8d20528 100644
--- a/drivers/media/video/bt8xx/bttv-driver.c
+++ b/drivers/media/video/bt8xx/bttv-driver.c
@@ -3152,6 +3152,7 @@  static unsigned int bttv_poll(struct file *file, poll_table *wait)
 	struct bttv_fh *fh = file->private_data;
 	struct bttv_buffer *buf;
 	enum v4l2_field field;
+	unsigned int rc = POLLERR;
 
 	if (V4L2_BUF_TYPE_VBI_CAPTURE == fh->type) {
 		if (!check_alloc_btres(fh->btv,fh,RESOURCE_VBI))
@@ -3160,9 +3161,10 @@  static unsigned int bttv_poll(struct file *file, poll_table *wait)
 	}
 
 	if (check_btres(fh,RESOURCE_VIDEO_STREAM)) {
+		mutex_lock(&fh->cap.vb_lock);
 		/* streaming capture */
 		if (list_empty(&fh->cap.stream))
-			return POLLERR;
+			return done;
 		buf = list_entry(fh->cap.stream.next,struct bttv_buffer,vb.stream);
 	} else {
 		/* read() capture */
@@ -3170,16 +3172,16 @@  static unsigned int bttv_poll(struct file *file, poll_table *wait)
 		if (NULL == fh->cap.read_buf) {
 			/* need to capture a new frame */
 			if (locked_btres(fh->btv,RESOURCE_VIDEO_STREAM))
-				goto err;
+				goto done;
 			fh->cap.read_buf = videobuf_sg_alloc(fh->cap.msize);
 			if (NULL == fh->cap.read_buf)
-				goto err;
+				goto done;
 			fh->cap.read_buf->memory = V4L2_MEMORY_USERPTR;
 			field = videobuf_next_field(&fh->cap);
 			if (0 != fh->cap.ops->buf_prepare(&fh->cap,fh->cap.read_buf,field)) {
 				kfree (fh->cap.read_buf);
 				fh->cap.read_buf = NULL;
-				goto err;
+				goto done;
 			}
 			fh->cap.ops->buf_queue(&fh->cap,fh->cap.read_buf);
 			fh->cap.read_off = 0;
@@ -3191,11 +3193,13 @@  static unsigned int bttv_poll(struct file *file, poll_table *wait)
 	poll_wait(file, &buf->vb.done, wait);
 	if (buf->vb.state == VIDEOBUF_DONE ||
 	    buf->vb.state == VIDEOBUF_ERROR)
-		return POLLIN|POLLRDNORM;
-	return 0;
-err:
+		rc =  POLLIN|POLLRDNORM;
+	else 
+		rc = 0;
+	
+done:
 	mutex_unlock(&fh->cap.vb_lock);
-	return POLLERR;
+	return rc;
 }
 
 static int bttv_open(struct file *file)
diff --git a/drivers/media/video/cx23885/cx23885-video.c b/drivers/media/video/cx23885/cx23885-video.c
index 68068c6..f542493 100644
--- a/drivers/media/video/cx23885/cx23885-video.c
+++ b/drivers/media/video/cx23885/cx23885-video.c
@@ -796,6 +796,7 @@  static unsigned int video_poll(struct file *file,
 {
 	struct cx23885_fh *fh = file->private_data;
 	struct cx23885_buffer *buf;
+	unsigned int rc = POLLERR;
 
 	if (V4L2_BUF_TYPE_VBI_CAPTURE == fh->type) {
 		if (!res_get(fh->dev, fh, RESOURCE_VBI))
@@ -803,23 +804,29 @@  static unsigned int video_poll(struct file *file,
 		return videobuf_poll_stream(file, &fh->vbiq, wait);
 	}
 
+	mutex_lock(&fh->vidq.vb_lock);
 	if (res_check(fh, RESOURCE_VIDEO)) {
 		/* streaming capture */
 		if (list_empty(&fh->vidq.stream))
-			return POLLERR;
+			goto done;
 		buf = list_entry(fh->vidq.stream.next,
 			struct cx23885_buffer, vb.stream);
 	} else {
 		/* read() capture */
 		buf = (struct cx23885_buffer *)fh->vidq.read_buf;
 		if (NULL == buf)
-			return POLLERR;
+			goto done;
 	}
 	poll_wait(file, &buf->vb.done, wait);
 	if (buf->vb.state == VIDEOBUF_DONE ||
 	    buf->vb.state == VIDEOBUF_ERROR)
-		return POLLIN|POLLRDNORM;
-	return 0;
+		rc =  POLLIN|POLLRDNORM;
+	else
+		rc = 0;
+
+done:
+	mutex_unlock(&fh->vidq.vb_lock);
+	return rc;
 }
 
 static int video_release(struct file *file)
diff --git a/drivers/media/video/cx88/cx88-video.c b/drivers/media/video/cx88/cx88-video.c
index b993d42..b1ca54b 100644
--- a/drivers/media/video/cx88/cx88-video.c
+++ b/drivers/media/video/cx88/cx88-video.c
@@ -869,6 +869,7 @@  video_poll(struct file *file, struct poll_table_struct *wait)
 {
 	struct cx8800_fh *fh = file->private_data;
 	struct cx88_buffer *buf;
+	unsigned int rc = POLLERR;
 
 	if (V4L2_BUF_TYPE_VBI_CAPTURE == fh->type) {
 		if (!res_get(fh->dev,fh,RESOURCE_VBI))
@@ -876,22 +877,28 @@  video_poll(struct file *file, struct poll_table_struct *wait)
 		return videobuf_poll_stream(file, &fh->vbiq, wait);
 	}
 
+	mutex_lock(&fh->vidq.vb_lock);
 	if (res_check(fh,RESOURCE_VIDEO)) {
 		/* streaming capture */
 		if (list_empty(&fh->vidq.stream))
-			return POLLERR;
+			goto done;
 		buf = list_entry(fh->vidq.stream.next,struct cx88_buffer,vb.stream);
 	} else {
 		/* read() capture */
 		buf = (struct cx88_buffer*)fh->vidq.read_buf;
 		if (NULL == buf)
-			return POLLERR;
+			goto done;
 	}
 	poll_wait(file, &buf->vb.done, wait);
 	if (buf->vb.state == VIDEOBUF_DONE ||
 	    buf->vb.state == VIDEOBUF_ERROR)
-		return POLLIN|POLLRDNORM;
-	return 0;
+		rc =  POLLIN|POLLRDNORM;
+	else
+		rc = 0;
+
+done:
+	mutex_unlock(&fh->vidq.vb_lock);
+	return rc;
 }
 
 static int video_release(struct file *file)