| Message ID | 20220920-resend-meta-v4-0-3ac355b66723@chromium.org |
|---|---|
| Headers | show |
| Series | Add Meta: to Metadata devices | expand |
Hi Ricardo, Thank you for the patch. On Fri, Dec 02, 2022 at 06:08:19PM +0100, Ricardo Ribalda wrote: > Some cameras have multiple data inputs (i.e. IR sensor and RGB sensor), > append a unique number to the device name. > > Fixes v4l2-compliance: > Media Controller ioctls: > fail: v4l2-test-media.cpp(205): v2_entity_names_set.find(key) != v2_entity_names_set.end() > test MEDIA_IOC_G_TOPOLOGY: FAIL > fail: v4l2-test-media.cpp(394): num_data_links != num_links > test MEDIA_IOC_ENUM_ENTITIES/LINKS: FAIL > > Signed-off-by: Ricardo Ribalda <ribalda@chromium.org> > --- > drivers/media/usb/uvc/uvc_driver.c | 3 ++- > 1 file changed, 2 insertions(+), 1 deletion(-) > > diff --git a/drivers/media/usb/uvc/uvc_driver.c b/drivers/media/usb/uvc/uvc_driver.c > index 215fb483efb0..f4032ebb3689 100644 > --- a/drivers/media/usb/uvc/uvc_driver.c > +++ b/drivers/media/usb/uvc/uvc_driver.c > @@ -1963,7 +1963,8 @@ int uvc_register_video_device(struct uvc_device *dev, > break; > } > > - strscpy(vdev->name, dev->name, sizeof(vdev->name)); > + snprintf(vdev->name, sizeof(vdev->name), "%s %u", dev->name, > + stream->header.bTerminalLink); This won't be perfect as the string is not guaranteed to fit in vdev->name, but I suppose it will help as a quick fix for some devices. How about the other devices ? Won't they still exhibit the above v4l2-compliance failure ? Isn't that something that will still affect Chrome OS devices ? The change should not cause any regression as big as in patch 1/3. However, unless I'm mistaken users will notice a device name change, especially when selecting a device in their web browser. Could that be a problem ? > /* > * Set the driver data before calling video_register_device, otherwise >
Hi Laurent On Mon, 5 Dec 2022 at 23:16, Laurent Pinchart <laurent.pinchart@ideasonboard.com> wrote: > > Hi Ricardo, > > Thank you for the patch. > > On Fri, Dec 02, 2022 at 06:08:19PM +0100, Ricardo Ribalda wrote: > > Some cameras have multiple data inputs (i.e. IR sensor and RGB sensor), > > append a unique number to the device name. > > > > Fixes v4l2-compliance: > > Media Controller ioctls: > > fail: v4l2-test-media.cpp(205): v2_entity_names_set.find(key) != v2_entity_names_set.end() > > test MEDIA_IOC_G_TOPOLOGY: FAIL > > fail: v4l2-test-media.cpp(394): num_data_links != num_links > > test MEDIA_IOC_ENUM_ENTITIES/LINKS: FAIL > > > > Signed-off-by: Ricardo Ribalda <ribalda@chromium.org> > > --- > > drivers/media/usb/uvc/uvc_driver.c | 3 ++- > > 1 file changed, 2 insertions(+), 1 deletion(-) > > > > diff --git a/drivers/media/usb/uvc/uvc_driver.c b/drivers/media/usb/uvc/uvc_driver.c > > index 215fb483efb0..f4032ebb3689 100644 > > --- a/drivers/media/usb/uvc/uvc_driver.c > > +++ b/drivers/media/usb/uvc/uvc_driver.c > > @@ -1963,7 +1963,8 @@ int uvc_register_video_device(struct uvc_device *dev, > > break; > > } > > > > - strscpy(vdev->name, dev->name, sizeof(vdev->name)); > > + snprintf(vdev->name, sizeof(vdev->name), "%s %u", dev->name, > > + stream->header.bTerminalLink); > > This won't be perfect as the string is not guaranteed to fit in > vdev->name, but I suppose it will help as a quick fix for some devices. > How about the other devices ? Won't they still exhibit the above > v4l2-compliance failure ? Isn't that something that will still affect > Chrome OS devices ? We could place the id first... but that will look bad: Eg: 1- My favorite camera Another option is to remove the last chars to fit the id. Eg: My favorite came-1 If you prefer any of those options or have a better idea I can implement that. > > The change should not cause any regression as big as in patch 1/3. > However, unless I'm mistaken users will notice a device name change, > especially when selecting a device in their web browser. Could that be a > problem ? I think the only side effect is that the first time that the kernel changes the naming convention, if there are more than one camera on the system, the video conference might pick a different camera. The good news is that the user will be presented with cameras with different names. Now some cameras show very confusing names: ribalda@alco:~/work/linux$ for a in /dev/video* ; do yavta -l $a| grep "Dell Webcam"; done Device `Dell Webcam WB7022' on `usb-0000:2d:00.0-1.2.3.1' (driver 'uvcvideo') supports video, capture, without mplanes. Device `Dell Webcam WB7022' on `usb-0000:2d:00.0-1.2.3.1' (driver 'uvcvideo') supports meta-data, capture, without mplanes. Device `Dell Webcam WB7022' on `usb-0000:2d:00.0-1.2.3.1' (driver 'uvcvideo') supports video, capture, without mplanes. Device `Dell Webcam WB7022' on `usb-0000:2d:00.0-1.2.3.1' (driver 'uvcvideo') supports meta-data, capture, without mplanes. > > > /* > > * Set the driver data before calling video_register_device, otherwise > > > > -- > Regards, > > Laurent Pinchart
Hi On Tue, 6 Dec 2022 at 00:02, Ricardo Ribalda <ribalda@chromium.org> wrote: > > Hi Laurent > > On Mon, 5 Dec 2022 at 23:16, Laurent Pinchart > <laurent.pinchart@ideasonboard.com> wrote: > > > > Hi Ricardo, > > > > Thank you for the patch. > > > > On Fri, Dec 02, 2022 at 06:08:19PM +0100, Ricardo Ribalda wrote: > > > Some cameras have multiple data inputs (i.e. IR sensor and RGB sensor), > > > append a unique number to the device name. > > > > > > Fixes v4l2-compliance: > > > Media Controller ioctls: > > > fail: v4l2-test-media.cpp(205): v2_entity_names_set.find(key) != v2_entity_names_set.end() > > > test MEDIA_IOC_G_TOPOLOGY: FAIL > > > fail: v4l2-test-media.cpp(394): num_data_links != num_links > > > test MEDIA_IOC_ENUM_ENTITIES/LINKS: FAIL > > > > > > Signed-off-by: Ricardo Ribalda <ribalda@chromium.org> > > > --- > > > drivers/media/usb/uvc/uvc_driver.c | 3 ++- > > > 1 file changed, 2 insertions(+), 1 deletion(-) > > > > > > diff --git a/drivers/media/usb/uvc/uvc_driver.c b/drivers/media/usb/uvc/uvc_driver.c > > > index 215fb483efb0..f4032ebb3689 100644 > > > --- a/drivers/media/usb/uvc/uvc_driver.c > > > +++ b/drivers/media/usb/uvc/uvc_driver.c > > > @@ -1963,7 +1963,8 @@ int uvc_register_video_device(struct uvc_device *dev, > > > break; > > > } > > > > > > - strscpy(vdev->name, dev->name, sizeof(vdev->name)); > > > + snprintf(vdev->name, sizeof(vdev->name), "%s %u", dev->name, > > > + stream->header.bTerminalLink); > > > > This won't be perfect as the string is not guaranteed to fit in > > vdev->name, but I suppose it will help as a quick fix for some devices. > > How about the other devices ? Won't they still exhibit the above > > v4l2-compliance failure ? Isn't that something that will still affect > > Chrome OS devices ? > > We could place the id first... but that will look bad: Eg: > > 1- My favorite camera > > Another option is to remove the last chars to fit the id. Eg: > > My favorite came-1 > > If you prefer any of those options or have a better idea I can implement that. @Laurent Any preference here? Thanks! > > > > > > The change should not cause any regression as big as in patch 1/3. > > However, unless I'm mistaken users will notice a device name change, > > especially when selecting a device in their web browser. Could that be a > > problem ? > > I think the only side effect is that the first time that the kernel > changes the naming convention, if there are more than one camera on > the system, the video conference might pick a different camera. > The good news is that the user will be presented with cameras with > different names. Now some cameras show very confusing names: > > ribalda@alco:~/work/linux$ for a in /dev/video* ; do yavta -l $a| grep > "Dell Webcam"; done > Device `Dell Webcam WB7022' on `usb-0000:2d:00.0-1.2.3.1' (driver > 'uvcvideo') supports video, capture, without mplanes. > Device `Dell Webcam WB7022' on `usb-0000:2d:00.0-1.2.3.1' (driver > 'uvcvideo') supports meta-data, capture, without mplanes. > Device `Dell Webcam WB7022' on `usb-0000:2d:00.0-1.2.3.1' (driver > 'uvcvideo') supports video, capture, without mplanes. > Device `Dell Webcam WB7022' on `usb-0000:2d:00.0-1.2.3.1' (driver > 'uvcvideo') supports meta-data, capture, without mplanes. > > > > > > > > /* > > > * Set the driver data before calling video_register_device, otherwise > > > > > > > -- > > Regards, > > > > Laurent Pinchart > > > > -- > Ricardo Ribalda
Hi Laurent On Wed, 21 Dec 2022 at 11:55, Laurent Pinchart <laurent.pinchart@ideasonboard.com> wrote: > > Hi Ricardo, > > On Wed, Dec 21, 2022 at 12:00:58AM +0100, Ricardo Ribalda wrote: > > On Tue, 6 Dec 2022 at 00:02, Ricardo Ribalda wrote: > > > On Mon, 5 Dec 2022 at 23:16, Laurent Pinchart wrote: > > > > On Fri, Dec 02, 2022 at 06:08:19PM +0100, Ricardo Ribalda wrote: > > > > > Some cameras have multiple data inputs (i.e. IR sensor and RGB sensor), > > Did you mean "data outputs" by the way ? > > > > > > append a unique number to the device name. > > > > > > > > > > Fixes v4l2-compliance: > > > > > Media Controller ioctls: > > > > > fail: v4l2-test-media.cpp(205): v2_entity_names_set.find(key) != v2_entity_names_set.end() > > > > > test MEDIA_IOC_G_TOPOLOGY: FAIL > > > > > fail: v4l2-test-media.cpp(394): num_data_links != num_links > > > > > test MEDIA_IOC_ENUM_ENTITIES/LINKS: FAIL > > > > > > > > > > Signed-off-by: Ricardo Ribalda <ribalda@chromium.org> > > > > > --- > > > > > drivers/media/usb/uvc/uvc_driver.c | 3 ++- > > > > > 1 file changed, 2 insertions(+), 1 deletion(-) > > > > > > > > > > diff --git a/drivers/media/usb/uvc/uvc_driver.c b/drivers/media/usb/uvc/uvc_driver.c > > > > > index 215fb483efb0..f4032ebb3689 100644 > > > > > --- a/drivers/media/usb/uvc/uvc_driver.c > > > > > +++ b/drivers/media/usb/uvc/uvc_driver.c > > > > > @@ -1963,7 +1963,8 @@ int uvc_register_video_device(struct uvc_device *dev, > > > > > break; > > > > > } > > > > > > > > > > - strscpy(vdev->name, dev->name, sizeof(vdev->name)); > > > > > + snprintf(vdev->name, sizeof(vdev->name), "%s %u", dev->name, > > > > > + stream->header.bTerminalLink); > > > > > > > > This won't be perfect as the string is not guaranteed to fit in > > > > vdev->name, but I suppose it will help as a quick fix for some devices. > > > > How about the other devices ? Won't they still exhibit the above > > > > v4l2-compliance failure ? Isn't that something that will still affect > > > > Chrome OS devices ? > > > > > > We could place the id first... but that will look bad: Eg: > > > > > > 1- My favorite camera > > > > > > Another option is to remove the last chars to fit the id. Eg: > > > > > > My favorite came-1 > > > > > > If you prefer any of those options or have a better idea I can implement that. > > > > @Laurent > > > > Any preference here? > > I think the latter is better. Could we do so only when there are > multiple video capture devices (excluding the metadata device) though ? > That way we won't have a weird "-n" suffix in the majority of use cases. > > > > > The change should not cause any regression as big as in patch 1/3. > > > > However, unless I'm mistaken users will notice a device name change, > > > > especially when selecting a device in their web browser. Could that be a > > > > problem ? > > > > > > I think the only side effect is that the first time that the kernel > > > changes the naming convention, if there are more than one camera on > > > the system, the video conference might pick a different camera. > > > The good news is that the user will be presented with cameras with > > > different names. Now some cameras show very confusing names: > > > > > > ribalda@alco:~/work/linux$ for a in /dev/video* ; do yavta -l $a| grep > > > "Dell Webcam"; done > > > Device `Dell Webcam WB7022' on `usb-0000:2d:00.0-1.2.3.1' (driver > > > 'uvcvideo') supports video, capture, without mplanes. > > > Device `Dell Webcam WB7022' on `usb-0000:2d:00.0-1.2.3.1' (driver > > > 'uvcvideo') supports meta-data, capture, without mplanes. > > > Device `Dell Webcam WB7022' on `usb-0000:2d:00.0-1.2.3.1' (driver > > > 'uvcvideo') supports video, capture, without mplanes. > > > Device `Dell Webcam WB7022' on `usb-0000:2d:00.0-1.2.3.1' (driver > > > 'uvcvideo') supports meta-data, capture, without mplanes. > > I'm tempted to add a new model read-only string control to overcome the > length limitation. It could then be combined with other information > (such as the location and supported pixel formats) to create a > user-friendly camera name by applications. Adding the vid:pid would be really useful! Mapping a /dev/videoX to vid:pid is kind of complicated now. Thanks! > > > > > > /* > > > > > * Set the driver data before calling video_register_device, otherwise > > > > > > > -- > Regards, > > Laurent Pinchart
Hi Ricardo, On Wed, Dec 21, 2022 at 11:57:48AM +0100, Ricardo Ribalda wrote: > On Wed, 21 Dec 2022 at 11:55, Laurent Pinchart wrote: > > On Wed, Dec 21, 2022 at 12:00:58AM +0100, Ricardo Ribalda wrote: > > > On Tue, 6 Dec 2022 at 00:02, Ricardo Ribalda wrote: > > > > On Mon, 5 Dec 2022 at 23:16, Laurent Pinchart wrote: > > > > > On Fri, Dec 02, 2022 at 06:08:19PM +0100, Ricardo Ribalda wrote: > > > > > > Some cameras have multiple data inputs (i.e. IR sensor and RGB sensor), > > > > Did you mean "data outputs" by the way ? > > > > > > > > append a unique number to the device name. > > > > > > > > > > > > Fixes v4l2-compliance: > > > > > > Media Controller ioctls: > > > > > > fail: v4l2-test-media.cpp(205): v2_entity_names_set.find(key) != v2_entity_names_set.end() > > > > > > test MEDIA_IOC_G_TOPOLOGY: FAIL > > > > > > fail: v4l2-test-media.cpp(394): num_data_links != num_links > > > > > > test MEDIA_IOC_ENUM_ENTITIES/LINKS: FAIL > > > > > > > > > > > > Signed-off-by: Ricardo Ribalda <ribalda@chromium.org> > > > > > > --- > > > > > > drivers/media/usb/uvc/uvc_driver.c | 3 ++- > > > > > > 1 file changed, 2 insertions(+), 1 deletion(-) > > > > > > > > > > > > diff --git a/drivers/media/usb/uvc/uvc_driver.c b/drivers/media/usb/uvc/uvc_driver.c > > > > > > index 215fb483efb0..f4032ebb3689 100644 > > > > > > --- a/drivers/media/usb/uvc/uvc_driver.c > > > > > > +++ b/drivers/media/usb/uvc/uvc_driver.c > > > > > > @@ -1963,7 +1963,8 @@ int uvc_register_video_device(struct uvc_device *dev, > > > > > > break; > > > > > > } > > > > > > > > > > > > - strscpy(vdev->name, dev->name, sizeof(vdev->name)); > > > > > > + snprintf(vdev->name, sizeof(vdev->name), "%s %u", dev->name, > > > > > > + stream->header.bTerminalLink); > > > > > > > > > > This won't be perfect as the string is not guaranteed to fit in > > > > > vdev->name, but I suppose it will help as a quick fix for some devices. > > > > > How about the other devices ? Won't they still exhibit the above > > > > > v4l2-compliance failure ? Isn't that something that will still affect > > > > > Chrome OS devices ? > > > > > > > > We could place the id first... but that will look bad: Eg: > > > > > > > > 1- My favorite camera > > > > > > > > Another option is to remove the last chars to fit the id. Eg: > > > > > > > > My favorite came-1 > > > > > > > > If you prefer any of those options or have a better idea I can implement that. > > > > > > @Laurent > > > > > > Any preference here? > > > > I think the latter is better. Could we do so only when there are > > multiple video capture devices (excluding the metadata device) though ? > > That way we won't have a weird "-n" suffix in the majority of use cases. > > > > > > > The change should not cause any regression as big as in patch 1/3. > > > > > However, unless I'm mistaken users will notice a device name change, > > > > > especially when selecting a device in their web browser. Could that be a > > > > > problem ? > > > > > > > > I think the only side effect is that the first time that the kernel > > > > changes the naming convention, if there are more than one camera on > > > > the system, the video conference might pick a different camera. > > > > The good news is that the user will be presented with cameras with > > > > different names. Now some cameras show very confusing names: > > > > > > > > ribalda@alco:~/work/linux$ for a in /dev/video* ; do yavta -l $a| grep > > > > "Dell Webcam"; done > > > > Device `Dell Webcam WB7022' on `usb-0000:2d:00.0-1.2.3.1' (driver > > > > 'uvcvideo') supports video, capture, without mplanes. > > > > Device `Dell Webcam WB7022' on `usb-0000:2d:00.0-1.2.3.1' (driver > > > > 'uvcvideo') supports meta-data, capture, without mplanes. > > > > Device `Dell Webcam WB7022' on `usb-0000:2d:00.0-1.2.3.1' (driver > > > > 'uvcvideo') supports video, capture, without mplanes. > > > > Device `Dell Webcam WB7022' on `usb-0000:2d:00.0-1.2.3.1' (driver > > > > 'uvcvideo') supports meta-data, capture, without mplanes. > > > > I'm tempted to add a new model read-only string control to overcome the > > length limitation. It could then be combined with other information > > (such as the location and supported pixel formats) to create a > > user-friendly camera name by applications. > > Adding the vid:pid would be really useful! Mapping a /dev/videoX to > vid:pid is kind of complicated now. libcamera can help there ;-) We already extract the vendor and product ID. They are only used to create the camera ID at the moment, they are not exposed to applications independently. That would be a good addition. Overall, device naming is something that we have decided *not* to handle in libcamera. We provide information to applications to help them construct a meaningful name, but don't create the name ourselves. This was decided because naming schemes are dependent on application use cases, and in many cases should be localized (e.g. "Front camera" and "Back camera" vs. "Etukamera" and "Takakamera"). > > > > > > /* > > > > > > * Set the driver data before calling video_register_device, otherwise > > > > > >
Hi Ricardo, On Wed, Dec 21, 2022 at 09:21:57PM +0100, Ricardo Ribalda wrote: > On Wed, 21 Dec 2022 at 12:23, Laurent Pinchart wrote: > > On Wed, Dec 21, 2022 at 11:57:48AM +0100, Ricardo Ribalda wrote: > > > On Wed, 21 Dec 2022 at 11:55, Laurent Pinchart wrote: > > > > On Wed, Dec 21, 2022 at 12:00:58AM +0100, Ricardo Ribalda wrote: > > > > > On Tue, 6 Dec 2022 at 00:02, Ricardo Ribalda wrote: > > > > > > On Mon, 5 Dec 2022 at 23:16, Laurent Pinchart wrote: > > > > > > > On Fri, Dec 02, 2022 at 06:08:19PM +0100, Ricardo Ribalda wrote: > > > > > > > > Some cameras have multiple data inputs (i.e. IR sensor and RGB sensor), > > > > > > > > Did you mean "data outputs" by the way ? > > > > > > > > > > > > append a unique number to the device name. > > > > > > > > > > > > > > > > Fixes v4l2-compliance: > > > > > > > > Media Controller ioctls: > > > > > > > > fail: v4l2-test-media.cpp(205): v2_entity_names_set.find(key) != v2_entity_names_set.end() > > > > > > > > test MEDIA_IOC_G_TOPOLOGY: FAIL > > > > > > > > fail: v4l2-test-media.cpp(394): num_data_links != num_links > > > > > > > > test MEDIA_IOC_ENUM_ENTITIES/LINKS: FAIL > > > > > > > > > > > > > > > > Signed-off-by: Ricardo Ribalda <ribalda@chromium.org> > > > > > > > > --- > > > > > > > > drivers/media/usb/uvc/uvc_driver.c | 3 ++- > > > > > > > > 1 file changed, 2 insertions(+), 1 deletion(-) > > > > > > > > > > > > > > > > diff --git a/drivers/media/usb/uvc/uvc_driver.c b/drivers/media/usb/uvc/uvc_driver.c > > > > > > > > index 215fb483efb0..f4032ebb3689 100644 > > > > > > > > --- a/drivers/media/usb/uvc/uvc_driver.c > > > > > > > > +++ b/drivers/media/usb/uvc/uvc_driver.c > > > > > > > > @@ -1963,7 +1963,8 @@ int uvc_register_video_device(struct uvc_device *dev, > > > > > > > > break; > > > > > > > > } > > > > > > > > > > > > > > > > - strscpy(vdev->name, dev->name, sizeof(vdev->name)); > > > > > > > > + snprintf(vdev->name, sizeof(vdev->name), "%s %u", dev->name, > > > > > > > > + stream->header.bTerminalLink); > > > > > > > > > > > > > > This won't be perfect as the string is not guaranteed to fit in > > > > > > > vdev->name, but I suppose it will help as a quick fix for some devices. > > > > > > > How about the other devices ? Won't they still exhibit the above > > > > > > > v4l2-compliance failure ? Isn't that something that will still affect > > > > > > > Chrome OS devices ? > > > > > > > > > > > > We could place the id first... but that will look bad: Eg: > > > > > > > > > > > > 1- My favorite camera > > > > > > > > > > > > Another option is to remove the last chars to fit the id. Eg: > > > > > > > > > > > > My favorite came-1 > > > > > > > > > > > > If you prefer any of those options or have a better idea I can implement that. > > > > > > > > > > @Laurent > > > > > > > > > > Any preference here? > > > > > > > > I think the latter is better. Could we do so only when there are > > > > multiple video capture devices (excluding the metadata device) though ? > > > > That way we won't have a weird "-n" suffix in the majority of use cases. > > > > > > > > > > > The change should not cause any regression as big as in patch 1/3. > > > > > > > However, unless I'm mistaken users will notice a device name change, > > > > > > > especially when selecting a device in their web browser. Could that be a > > > > > > > problem ? > > > > > > > > > > > > I think the only side effect is that the first time that the kernel > > > > > > changes the naming convention, if there are more than one camera on > > > > > > the system, the video conference might pick a different camera. > > > > > > The good news is that the user will be presented with cameras with > > > > > > different names. Now some cameras show very confusing names: > > > > > > > > > > > > ribalda@alco:~/work/linux$ for a in /dev/video* ; do yavta -l $a| grep > > > > > > "Dell Webcam"; done > > > > > > Device `Dell Webcam WB7022' on `usb-0000:2d:00.0-1.2.3.1' (driver > > > > > > 'uvcvideo') supports video, capture, without mplanes. > > > > > > Device `Dell Webcam WB7022' on `usb-0000:2d:00.0-1.2.3.1' (driver > > > > > > 'uvcvideo') supports meta-data, capture, without mplanes. > > > > > > Device `Dell Webcam WB7022' on `usb-0000:2d:00.0-1.2.3.1' (driver > > > > > > 'uvcvideo') supports video, capture, without mplanes. > > > > > > Device `Dell Webcam WB7022' on `usb-0000:2d:00.0-1.2.3.1' (driver > > > > > > 'uvcvideo') supports meta-data, capture, without mplanes. > > > > > > > > I'm tempted to add a new model read-only string control to overcome the > > > > length limitation. It could then be combined with other information > > > > (such as the location and supported pixel formats) to create a > > > > user-friendly camera name by applications. > > > > > > Adding the vid:pid would be really useful! Mapping a /dev/videoX to > > > vid:pid is kind of complicated now. > > > > libcamera can help there ;-) We already extract the vendor and product > > ID. They are only used to create the camera ID at the moment, they are > > not exposed to applications independently. That would be a good > > addition. > > > > Overall, device naming is something that we have decided *not* to handle > > in libcamera. We provide information to applications to help them > > construct a meaningful name, but don't create the name ourselves. This > > was decided because naming schemes are dependent on application use > > cases, and in many cases should be localized (e.g. "Front camera" and > > "Back camera" vs. "Etukamera" and "Takakamera"). > > Thanks for the explanation! > > My use case is: vendor apps for doing provisioning or low level > testing. Libcamera would be a bit too much for that ;) > > Most of the time they do not get an image, but set fancy controls. I see what you mean. libcamera isn't the right tool for that indeed, but maybe the additional complexity of looking up the VID:PID isn't such a big deal in those cases ? It's not that complicated using sysfs, and can even be done quite simply with a shell script. Maybe a standard simple script in v4l-utils (or in another location) could help ? > > > > > > > > /* > > > > > > > > * Set the driver data before calling video_register_device, otherwise > > > > > > > >
On Wed, Dec 21, 2022 at 10:54:50PM +0000, Mauro Carvalho Chehab wrote: > Em Thu, 22 Dec 2022 00:24:44 +0200 > Laurent Pinchart <laurent.pinchart@ideasonboard.com> escreveu: > > > Hi Mauro, > > > > On Wed, Dec 21, 2022 at 10:02:48PM +0000, Mauro Carvalho Chehab wrote: > > > Em Tue, 6 Dec 2022 00:02:22 +0100 Ricardo Ribalda escreveu: > > > > On Mon, 5 Dec 2022 at 23:16, Laurent Pinchart wrote: > > > > > On Fri, Dec 02, 2022 at 06:08:19PM +0100, Ricardo Ribalda wrote: > > > > > > Some cameras have multiple data inputs (i.e. IR sensor and RGB sensor), > > > > > > append a unique number to the device name. > > > > > > > > > > > > Fixes v4l2-compliance: > > > > > > Media Controller ioctls: > > > > > > fail: v4l2-test-media.cpp(205): v2_entity_names_set.find(key) != v2_entity_names_set.end() > > > > > > test MEDIA_IOC_G_TOPOLOGY: FAIL > > > > > > fail: v4l2-test-media.cpp(394): num_data_links != num_links > > > > > > test MEDIA_IOC_ENUM_ENTITIES/LINKS: FAIL > > > > > > > > > > > > Signed-off-by: Ricardo Ribalda <ribalda@chromium.org> > > > > > > --- > > > > > > drivers/media/usb/uvc/uvc_driver.c | 3 ++- > > > > > > 1 file changed, 2 insertions(+), 1 deletion(-) > > > > > > > > > > > > diff --git a/drivers/media/usb/uvc/uvc_driver.c b/drivers/media/usb/uvc/uvc_driver.c > > > > > > index 215fb483efb0..f4032ebb3689 100644 > > > > > > --- a/drivers/media/usb/uvc/uvc_driver.c > > > > > > +++ b/drivers/media/usb/uvc/uvc_driver.c > > > > > > @@ -1963,7 +1963,8 @@ int uvc_register_video_device(struct uvc_device *dev, > > > > > > break; > > > > > > } > > > > > > > > > > > > - strscpy(vdev->name, dev->name, sizeof(vdev->name)); > > > > > > + snprintf(vdev->name, sizeof(vdev->name), "%s %u", dev->name, > > > > > > + stream->header.bTerminalLink); > > > > > > > > > > This won't be perfect as the string is not guaranteed to fit in > > > > > vdev->name, but I suppose it will help as a quick fix for some devices. > > > > > How about the other devices ? Won't they still exhibit the above > > > > > v4l2-compliance failure ? Isn't that something that will still affect > > > > > Chrome OS devices ? > > > > > > > > We could place the id first... but that will look bad: Eg: > > > > > > > > 1- My favorite camera > > > > > > > > Another option is to remove the last chars to fit the id. Eg: > > > > > > > > My favorite came-1 > > > > > > > > If you prefer any of those options or have a better idea I can implement that. > > > > > > > > > The change should not cause any regression as big as in patch 1/3. > > > > > However, unless I'm mistaken users will notice a device name change, > > > > > especially when selecting a device in their web browser. Could that be a > > > > > problem ? > > > > > > > > I think the only side effect is that the first time that the kernel > > > > changes the naming convention, if there are more than one camera on > > > > the system, the video conference might pick a different camera. > > > > The good news is that the user will be presented with cameras with > > > > different names. Now some cameras show very confusing names: > > > > > > > > ribalda@alco:~/work/linux$ for a in /dev/video* ; do yavta -l $a| grep > > > > "Dell Webcam"; done > > > > Device `Dell Webcam WB7022' on `usb-0000:2d:00.0-1.2.3.1' (driver > > > > 'uvcvideo') supports video, capture, without mplanes. > > > > Device `Dell Webcam WB7022' on `usb-0000:2d:00.0-1.2.3.1' (driver > > > > 'uvcvideo') supports meta-data, capture, without mplanes. > > > > Device `Dell Webcam WB7022' on `usb-0000:2d:00.0-1.2.3.1' (driver > > > > 'uvcvideo') supports video, capture, without mplanes. > > > > Device `Dell Webcam WB7022' on `usb-0000:2d:00.0-1.2.3.1' (driver > > > > 'uvcvideo') supports meta-data, capture, without mplanes. > > > > > > That is bad, as some apps like camorama actually store the user > > > preferences (last used resolution and fps), preserving them the next > > > time the camera with the same name is used. > > > > > > In the specific case of camorama, it uses the by-id filename, which is > > > derived from the name, as stored at: > > > > > > $ ls -la /dev/v4l/by-id/usb-Quanta_HD_Camera_0001-video-index* > > > lrwxrwxrwx 1 root root 12 dez 21 09:59 /dev/v4l/by-id/usb-Quanta_HD_Camera_0001-video-index0 -> ../../video0 > > > lrwxrwxrwx 1 root root 12 dez 21 09:59 /dev/v4l/by-id/usb-Quanta_HD_Camera_0001-video-index1 -> ../../video1 > > > > > > With this change, not only the camera name will become bigger (and may > > > end losing the index0/index1 data), but it will also lost the stored > > > preferences on apps like camorama, causing regressions. > > > > > > It sounds a lot easier to teach udev to change the name on an unique > > > way, on machines where you need it. > > > > It's not a udev issue, it's an API compliance problem, entity names in a > > media controller graph must be unique, and they are not. > > Then the right fix would be inside the media controller naming > logic, in a way that it will ensure unique names. It sounds to me > that mc core should then check, at device's register time, if the > name was already used. If so, change it to be unique. The entity name and video device name are one and the same. > > Losing the stored preference is possibly inconvenient in some cases, but > > I don't think it's a real blocker. > > If it causes userspace regressions, then it is a blocker. I wouldn't necessarily call this a regression.
Metadata devices usually companion "real" devices. In order to distinguish them properly, add the Meta: prefix to their names. Also, add a unique suffix to all the uvc devices, to multisensor cameras do not show the same names for all their devices (IR, RBG....). v4: - Rebase to latest master v3: - Add the meta logic to the core v2: uvc: Restore old vdev name To: Mauro Carvalho Chehab <mchehab@kernel.org> To: Laurent Pinchart <laurent.pinchart@ideasonboard.com> To: Yunke Cao <yunkec@chromium.org> To: Sergey Senozhatsky <senozhatsky@chromium.org> Cc: linux-media@vger.kernel.org Cc: linux-kernel@vger.kernel.org Cc: Mauro Carvalho Chehab <mchehab+huawei@kernel.org> Signed-off-by: Ricardo Ribalda <ribalda@chromium.org> --- Changes in v4: - Link to v3: https://lore.kernel.org/r/20220920-resend-meta-v1-0-dfcfba923204@chromium.org --- Ricardo Ribalda (3): media: v4l2-dev.c: Add Meta: to the name of metadata devices media: Documentation/driver-api: Document device name media: uvcvideo: Add a unique suffix to camera names Documentation/driver-api/media/v4l2-dev.rst | 4 +++- drivers/media/usb/uvc/uvc_driver.c | 3 ++- drivers/media/v4l2-core/v4l2-dev.c | 9 +++++++++ 3 files changed, 14 insertions(+), 2 deletions(-) --- base-commit: a4412fdd49dc011bcc2c0d81ac4cab7457092650 change-id: 20220920-resend-meta-435c30209235 Best regards,