diff options
Diffstat (limited to 'drivers/media/video/em28xx/em28xx-video.c')
| -rw-r--r-- | drivers/media/video/em28xx/em28xx-video.c | 30 |
1 files changed, 22 insertions, 8 deletions
diff --git a/drivers/media/video/em28xx/em28xx-video.c b/drivers/media/video/em28xx/em28xx-video.c index f0191779a8e..8a4d221a4fe 100644 --- a/drivers/media/video/em28xx/em28xx-video.c +++ b/drivers/media/video/em28xx/em28xx-video.c @@ -416,6 +416,9 @@ em28xx_v4l2_read(struct file *filp, char __user * buf, size_t count, struct em28xx_fh *fh = filp->private_data; struct em28xx *dev = fh->dev; + /* FIXME: read() is not prepared to allow changing the video + resolution while streaming. Seems a bug at em28xx_set_fmt + */ if (unlikely(res_get(fh) < 0)) return -EBUSY; @@ -498,25 +501,36 @@ em28xx_v4l2_read(struct file *filp, char __user * buf, size_t count, mutex_unlock(&dev->lock); return -ENODEV; } + dev->video_bytesread = 0; } f = list_entry(dev->outqueue.prev, struct em28xx_frame_t, frame); - spin_lock_irqsave(&dev->queue_lock, lock_flags); - list_for_each_entry(i, &dev->outqueue, frame) - i->state = F_UNUSED; - INIT_LIST_HEAD(&dev->outqueue); - spin_unlock_irqrestore(&dev->queue_lock, lock_flags); - em28xx_queue_unusedframes(dev); if (count > f->buf.length) count = f->buf.length; - if (copy_to_user(buf, f->bufmem, count)) { - mutex_unlock(&dev->lock); + if ((dev->video_bytesread + count) > dev->frame_size) + count = dev->frame_size - dev->video_bytesread; + + if (copy_to_user(buf, f->bufmem+dev->video_bytesread, count)) { + em28xx_err("Error while copying to user\n"); return -EFAULT; } + dev->video_bytesread += count; + + if (dev->video_bytesread == dev->frame_size) { + spin_lock_irqsave(&dev->queue_lock, lock_flags); + list_for_each_entry(i, &dev->outqueue, frame) + i->state = F_UNUSED; + INIT_LIST_HEAD(&dev->outqueue); + spin_unlock_irqrestore(&dev->queue_lock, lock_flags); + + em28xx_queue_unusedframes(dev); + dev->video_bytesread = 0; + } + *f_pos += count; mutex_unlock(&dev->lock); |