| Message ID | 1457539401-11515-7-git-send-email-ao2@ao2.it (mailing list archive) |
|---|---|
| State | Rejected |
| Headers | show |
On 03/09/16 17:03, Antonio Ospite wrote: > When calling VIDIOC_REQBUFS v4l2-compliance fails with this message: > > fail: v4l2-test-buffers.cpp(476): q.reqbufs(node, 1) > test VIDIOC_REQBUFS/CREATE_BUFS/QUERYBUF: FAIL > > By looking at the v4l2-compliance code the failure happens when trying > to request V4L2_MEMORY_USERPTR buffers without freeing explicitly the > previously allocated V4L2_MEMORY_MMAP buffers. > > This would suggest that when changing the memory field in struct > v4l2_requestbuffers the driver is supposed to free automatically any > previous allocated buffers, and looking for inspiration at the code in > drivers/media/v4l2-core/videobuf2-core.c::vb2_core_reqbufs() seems to > confirm this interpretation; however gspca is just returning -EBUSY in > this case. > > Removing the special handling for the case of a different memory value > fixes the compliance failure. > > Signed-off-by: Antonio Ospite <ao2@ao2.it> > --- > > This should be safe, but I'd really like a comment from someone with a more > global knowledge of v4l2. > > If my interpretation about how drivers should behave when the value of the > memory field changes is correct, I could send also a documentation update for > Documentation/DocBook/media/v4l/vidioc-reqbufs.xml Your interpretation is correct. Calling REQBUFS again should discard the old buffers and re-allocate new ones. Except, of course, if the old buffers are in use, then -EBUSY should be returned. Regards, Hans > > Just let me know. > > Thanks, > Antonio > > > drivers/media/usb/gspca/gspca.c | 7 ------- > 1 file changed, 7 deletions(-) > > diff --git a/drivers/media/usb/gspca/gspca.c b/drivers/media/usb/gspca/gspca.c > index 84b0d6a..915b6c7 100644 > --- a/drivers/media/usb/gspca/gspca.c > +++ b/drivers/media/usb/gspca/gspca.c > @@ -1402,13 +1402,6 @@ static int vidioc_reqbufs(struct file *file, void *priv, > if (mutex_lock_interruptible(&gspca_dev->queue_lock)) > return -ERESTARTSYS; > > - if (gspca_dev->memory != GSPCA_MEMORY_NO > - && gspca_dev->memory != GSPCA_MEMORY_READ > - && gspca_dev->memory != rb->memory) { > - ret = -EBUSY; > - goto out; > - } > - > /* only one file may do the capture */ > if (gspca_dev->capt_file != NULL > && gspca_dev->capt_file != file) { > -- To unsubscribe from this list: send the line "unsubscribe linux-media" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
Hi, On 09-03-16 17:03, Antonio Ospite wrote: > When calling VIDIOC_REQBUFS v4l2-compliance fails with this message: > > fail: v4l2-test-buffers.cpp(476): q.reqbufs(node, 1) > test VIDIOC_REQBUFS/CREATE_BUFS/QUERYBUF: FAIL > > By looking at the v4l2-compliance code the failure happens when trying > to request V4L2_MEMORY_USERPTR buffers without freeing explicitly the > previously allocated V4L2_MEMORY_MMAP buffers. > > This would suggest that when changing the memory field in struct > v4l2_requestbuffers the driver is supposed to free automatically any > previous allocated buffers, and looking for inspiration at the code in > drivers/media/v4l2-core/videobuf2-core.c::vb2_core_reqbufs() seems to > confirm this interpretation; however gspca is just returning -EBUSY in > this case. > > Removing the special handling for the case of a different memory value > fixes the compliance failure. > > Signed-off-by: Antonio Ospite <ao2@ao2.it> > --- > > This should be safe, but I'd really like a comment from someone with a more > global knowledge of v4l2. > > If my interpretation about how drivers should behave when the value of the > memory field changes is correct, I could send also a documentation update for > Documentation/DocBook/media/v4l/vidioc-reqbufs.xml > > Just let me know. > > Thanks, > Antonio > > > drivers/media/usb/gspca/gspca.c | 7 ------- > 1 file changed, 7 deletions(-) > > diff --git a/drivers/media/usb/gspca/gspca.c b/drivers/media/usb/gspca/gspca.c > index 84b0d6a..915b6c7 100644 > --- a/drivers/media/usb/gspca/gspca.c > +++ b/drivers/media/usb/gspca/gspca.c > @@ -1402,13 +1402,6 @@ static int vidioc_reqbufs(struct file *file, void *priv, > if (mutex_lock_interruptible(&gspca_dev->queue_lock)) > return -ERESTARTSYS; > > - if (gspca_dev->memory != GSPCA_MEMORY_NO > - && gspca_dev->memory != GSPCA_MEMORY_READ > - && gspca_dev->memory != rb->memory) { > - ret = -EBUSY; > - goto out; > - } > - reqbufs is used internally and this change will allow changing gspca_dev->memory from USERPTR / MMAP to GSPCA_MEMORY_READ please replace this check with a check to only allow rb->memory to be GSPCA_MEMORY_READ when coming from GSPCA_MEMORY_NO or GSPCA_MEMORY_READ Regards, Hans > /* only one file may do the capture */ > if (gspca_dev->capt_file != NULL > && gspca_dev->capt_file != file) { > -- To unsubscribe from this list: send the line "unsubscribe linux-media" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
On Thu, 10 Mar 2016 15:54:37 +0100 Hans de Goede <hdegoede@redhat.com> wrote: > Hi, > > On 09-03-16 17:03, Antonio Ospite wrote: > > When calling VIDIOC_REQBUFS v4l2-compliance fails with this message: > > > > fail: v4l2-test-buffers.cpp(476): q.reqbufs(node, 1) > > test VIDIOC_REQBUFS/CREATE_BUFS/QUERYBUF: FAIL > > > > By looking at the v4l2-compliance code the failure happens when trying > > to request V4L2_MEMORY_USERPTR buffers without freeing explicitly the > > previously allocated V4L2_MEMORY_MMAP buffers. > > > > This would suggest that when changing the memory field in struct > > v4l2_requestbuffers the driver is supposed to free automatically any > > previous allocated buffers, and looking for inspiration at the code in > > drivers/media/v4l2-core/videobuf2-core.c::vb2_core_reqbufs() seems to > > confirm this interpretation; however gspca is just returning -EBUSY in > > this case. > > > > Removing the special handling for the case of a different memory value > > fixes the compliance failure. > > > > Signed-off-by: Antonio Ospite <ao2@ao2.it> > > --- > > > > This should be safe, but I'd really like a comment from someone with a more > > global knowledge of v4l2. > > > > If my interpretation about how drivers should behave when the value of the > > memory field changes is correct, I could send also a documentation update for > > Documentation/DocBook/media/v4l/vidioc-reqbufs.xml > > > > Just let me know. > > > > Thanks, > > Antonio > > > > > > drivers/media/usb/gspca/gspca.c | 7 ------- > > 1 file changed, 7 deletions(-) > > > > diff --git a/drivers/media/usb/gspca/gspca.c b/drivers/media/usb/gspca/gspca.c > > index 84b0d6a..915b6c7 100644 > > --- a/drivers/media/usb/gspca/gspca.c > > +++ b/drivers/media/usb/gspca/gspca.c > > @@ -1402,13 +1402,6 @@ static int vidioc_reqbufs(struct file *file, void *priv, > > if (mutex_lock_interruptible(&gspca_dev->queue_lock)) > > return -ERESTARTSYS; > > > > - if (gspca_dev->memory != GSPCA_MEMORY_NO > > - && gspca_dev->memory != GSPCA_MEMORY_READ > > - && gspca_dev->memory != rb->memory) { > > - ret = -EBUSY; > > - goto out; > > - } > > - > > reqbufs is used internally and this change will allow changing > gspca_dev->memory from USERPTR / MMAP to GSPCA_MEMORY_READ > please replace this check with a check to only allow > rb->memory to be GSPCA_MEMORY_READ when coming from GSPCA_MEMORY_NO > or GSPCA_MEMORY_READ > OK, thanks, I'll take a look again later this week. In the meantime, if patches from 1 to 5 are OK, can we have them merged so I will just resubmit the last two in the set? Ciao, Antonio
Hi, On 14-03-16 16:02, Antonio Ospite wrote: > On Thu, 10 Mar 2016 15:54:37 +0100 > Hans de Goede <hdegoede@redhat.com> wrote: > >> Hi, >> >> On 09-03-16 17:03, Antonio Ospite wrote: >>> When calling VIDIOC_REQBUFS v4l2-compliance fails with this message: >>> >>> fail: v4l2-test-buffers.cpp(476): q.reqbufs(node, 1) >>> test VIDIOC_REQBUFS/CREATE_BUFS/QUERYBUF: FAIL >>> >>> By looking at the v4l2-compliance code the failure happens when trying >>> to request V4L2_MEMORY_USERPTR buffers without freeing explicitly the >>> previously allocated V4L2_MEMORY_MMAP buffers. >>> >>> This would suggest that when changing the memory field in struct >>> v4l2_requestbuffers the driver is supposed to free automatically any >>> previous allocated buffers, and looking for inspiration at the code in >>> drivers/media/v4l2-core/videobuf2-core.c::vb2_core_reqbufs() seems to >>> confirm this interpretation; however gspca is just returning -EBUSY in >>> this case. >>> >>> Removing the special handling for the case of a different memory value >>> fixes the compliance failure. >>> >>> Signed-off-by: Antonio Ospite <ao2@ao2.it> >>> --- >>> >>> This should be safe, but I'd really like a comment from someone with a more >>> global knowledge of v4l2. >>> >>> If my interpretation about how drivers should behave when the value of the >>> memory field changes is correct, I could send also a documentation update for >>> Documentation/DocBook/media/v4l/vidioc-reqbufs.xml >>> >>> Just let me know. >>> >>> Thanks, >>> Antonio >>> >>> >>> drivers/media/usb/gspca/gspca.c | 7 ------- >>> 1 file changed, 7 deletions(-) >>> >>> diff --git a/drivers/media/usb/gspca/gspca.c b/drivers/media/usb/gspca/gspca.c >>> index 84b0d6a..915b6c7 100644 >>> --- a/drivers/media/usb/gspca/gspca.c >>> +++ b/drivers/media/usb/gspca/gspca.c >>> @@ -1402,13 +1402,6 @@ static int vidioc_reqbufs(struct file *file, void *priv, >>> if (mutex_lock_interruptible(&gspca_dev->queue_lock)) >>> return -ERESTARTSYS; >>> >>> - if (gspca_dev->memory != GSPCA_MEMORY_NO >>> - && gspca_dev->memory != GSPCA_MEMORY_READ >>> - && gspca_dev->memory != rb->memory) { >>> - ret = -EBUSY; >>> - goto out; >>> - } >>> - >> >> reqbufs is used internally and this change will allow changing >> gspca_dev->memory from USERPTR / MMAP to GSPCA_MEMORY_READ >> please replace this check with a check to only allow >> rb->memory to be GSPCA_MEMORY_READ when coming from GSPCA_MEMORY_NO >> or GSPCA_MEMORY_READ >> > > OK, thanks, I'll take a look again later this week. > > In the meantime, if patches from 1 to 5 are OK, can we have them merged > so I will just resubmit the last two in the set? Not sure when I'll have time to do this, I would prefer to also take v2 of patch 6 and 7 while at it. But I agree that there is no need to pick op patches 1 - 5. I'll pick them up from patchwork when I've time. Regards, Hans -- To unsubscribe from this list: send the line "unsubscribe linux-media" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
diff --git a/drivers/media/usb/gspca/gspca.c b/drivers/media/usb/gspca/gspca.c index 84b0d6a..915b6c7 100644 --- a/drivers/media/usb/gspca/gspca.c +++ b/drivers/media/usb/gspca/gspca.c @@ -1402,13 +1402,6 @@ static int vidioc_reqbufs(struct file *file, void *priv, if (mutex_lock_interruptible(&gspca_dev->queue_lock)) return -ERESTARTSYS; - if (gspca_dev->memory != GSPCA_MEMORY_NO - && gspca_dev->memory != GSPCA_MEMORY_READ - && gspca_dev->memory != rb->memory) { - ret = -EBUSY; - goto out; - } - /* only one file may do the capture */ if (gspca_dev->capt_file != NULL && gspca_dev->capt_file != file) {
When calling VIDIOC_REQBUFS v4l2-compliance fails with this message: fail: v4l2-test-buffers.cpp(476): q.reqbufs(node, 1) test VIDIOC_REQBUFS/CREATE_BUFS/QUERYBUF: FAIL By looking at the v4l2-compliance code the failure happens when trying to request V4L2_MEMORY_USERPTR buffers without freeing explicitly the previously allocated V4L2_MEMORY_MMAP buffers. This would suggest that when changing the memory field in struct v4l2_requestbuffers the driver is supposed to free automatically any previous allocated buffers, and looking for inspiration at the code in drivers/media/v4l2-core/videobuf2-core.c::vb2_core_reqbufs() seems to confirm this interpretation; however gspca is just returning -EBUSY in this case. Removing the special handling for the case of a different memory value fixes the compliance failure. Signed-off-by: Antonio Ospite <ao2@ao2.it> --- This should be safe, but I'd really like a comment from someone with a more global knowledge of v4l2. If my interpretation about how drivers should behave when the value of the memory field changes is correct, I could send also a documentation update for Documentation/DocBook/media/v4l/vidioc-reqbufs.xml Just let me know. Thanks, Antonio drivers/media/usb/gspca/gspca.c | 7 ------- 1 file changed, 7 deletions(-)