* [PATCH v4] media: uvcvideo: Set V4L2_CTRL_FLAG_DISABLED during queryctrl errors
@ 2025-01-11 9:57 Ricardo Ribalda
2025-02-23 17:03 ` Laurent Pinchart
0 siblings, 1 reply; 6+ messages in thread
From: Ricardo Ribalda @ 2025-01-11 9:57 UTC (permalink / raw)
To: Hans Verkuil, Laurent Pinchart, Hans de Goede, Mauro Carvalho Chehab
Cc: linux-media, linux-kernel, Ricardo Ribalda
To implement VIDIOC_QUERYCTRL, we need to know the minimum, maximum,
step and flags of the control. For some of the controls, this involves
querying the actual hardware.
Some non-compliant cameras produce errors when we query them. Right now,
we populate that error to userspace. When an error happens, the v4l2
framework does not copy the v4l2_queryctrl struct to userspace. Also,
userspace apps are not ready to handle any other error than -EINVAL.
One of the main usecases of VIDIOC_QUERYCTRL is enumerating the controls
of a device. This is done using the V4L2_CTRL_FLAG_NEXT_CTRL flag. In
that usecase, a non-compliant control will make it almost impossible to
enumerate all controls of the device.
A control with an invalid max/min/step/flags is better than non being
able to enumerate the rest of the controls.
This patch makes VIDIOC_QUERYCTRL return 0 in all the error cases
different than -EINVAL, introduces a warning in dmesg so we can
have a trace of what has happened and sets the V4L2_CTRL_FLAG_DISABLED.
Signed-off-by: Ricardo Ribalda <ribalda@chromium.org>
---
Hi 2*Hans and Laurent!
I came around a device that was listing just a couple of controls when
it should be listing much more.
Some debugging latter I found that the device was returning -EIO when
all the focal controls were read.
Lots of good arguments in favor/against this patch in the v1. Please
check!
Without this patch:
$ v4l2-ctl --list-ctrls
auto_exposure 0x009a0901 (menu) : min=0 max=3 default=3 value=3 (Aperture Priority Mode)
exposure_time_absolute 0x009a0902 (int) : min=50 max=10000 step=1 default=166 value=166 flags=inactive
exposure_dynamic_framerate 0x009a0903 (bool) : default=0 value=0
region_of_interest_auto_control 0x009a1902 (bitmask): max=0x00000001 default=0x00000001 value=1
With this patch:
$ v4l2-ctl --list-ctrls
auto_exposure 0x009a0901 (menu) : min=0 max=3 default=3 value=3 (Aperture Priority Mode)
exposure_time_absolute 0x009a0902 (int) : min=50 max=10000 step=1 default=166 value=166 flags=inactive
exposure_dynamic_framerate 0x009a0903 (bool) : default=0 value=0
error 5 getting ext_ctrl Focus, Absolute
error 5 getting ext_ctrl Focus, Automatic Continuous
region_of_interest_rectangle 0x009a1901 (unknown): type=107 value=unsupported payload type flags=has-payload
region_of_interest_auto_control 0x009a1902 (bitmask): max=0x00000001 default=0x00000001 value=1
--
---
Changes in v4:
- Display control name (Thanks Hans)
- Link to v3: https://lore.kernel.org/r/20250107-uvc-eaccess-v3-1-99f3335d5133@chromium.org
Changes in v3:
- Add a retry mechanism during error.
- Set V4L2_CTRL_FLAG_DISABLED flag.
- Link to v2: https://lore.kernel.org/r/20241219-uvc-eaccess-v2-1-bf6520c8b86d@chromium.org
Changes in v2:
- Never return error, even if we are not enumerating the controls
- Improve commit message.
- Link to v1: https://lore.kernel.org/r/20241213-uvc-eaccess-v1-1-62e0b4fcc634@chromium.org
---
drivers/media/usb/uvc/uvc_ctrl.c | 43 ++++++++++++++++++++++++++++++++--------
1 file changed, 35 insertions(+), 8 deletions(-)
diff --git a/drivers/media/usb/uvc/uvc_ctrl.c b/drivers/media/usb/uvc/uvc_ctrl.c
index 4e58476d305e..9d7812e8572d 100644
--- a/drivers/media/usb/uvc/uvc_ctrl.c
+++ b/drivers/media/usb/uvc/uvc_ctrl.c
@@ -1280,6 +1280,8 @@ static u32 uvc_get_ctrl_bitmap(struct uvc_control *ctrl,
return ~0;
}
+#define MAX_QUERY_RETRIES 2
+
static int __uvc_query_v4l2_ctrl(struct uvc_video_chain *chain,
struct uvc_control *ctrl,
struct uvc_control_mapping *mapping,
@@ -1305,19 +1307,44 @@ static int __uvc_query_v4l2_ctrl(struct uvc_video_chain *chain,
__uvc_find_control(ctrl->entity, mapping->master_id,
&master_map, &master_ctrl, 0);
if (master_ctrl && (master_ctrl->info.flags & UVC_CTRL_FLAG_GET_CUR)) {
+ unsigned int retries;
s32 val;
- int ret = __uvc_ctrl_get(chain, master_ctrl, master_map, &val);
- if (ret < 0)
- return ret;
+ int ret;
- if (val != mapping->master_manual)
- v4l2_ctrl->flags |= V4L2_CTRL_FLAG_INACTIVE;
+ for (retries = 0; retries < MAX_QUERY_RETRIES; retries++) {
+ ret = __uvc_ctrl_get(chain, master_ctrl, master_map,
+ &val);
+ if (ret >= 0)
+ break;
+ }
+
+ if (ret < 0) {
+ dev_warn_ratelimited(&chain->dev->udev->dev,
+ "UVC non compliance: Error %d querying master control %x (%s)\n",
+ ret, master_map->id,
+ uvc_map_get_name(master_map));
+ } else if (val != mapping->master_manual) {
+ v4l2_ctrl->flags |= V4L2_CTRL_FLAG_INACTIVE;
+ }
}
if (!ctrl->cached) {
- int ret = uvc_ctrl_populate_cache(chain, ctrl);
- if (ret < 0)
- return ret;
+ unsigned int retries;
+ int ret;
+
+ for (retries = 0; retries < MAX_QUERY_RETRIES; retries++) {
+ ret = uvc_ctrl_populate_cache(chain, ctrl);
+ if (ret >= 0)
+ break;
+ }
+
+ if (ret < 0) {
+ dev_warn_ratelimited(&chain->dev->udev->dev,
+ "UVC non compliance: Error %d populating cache of control %x (%s)\n",
+ ret, mapping->id,
+ uvc_map_get_name(mapping));
+ v4l2_ctrl->flags |= V4L2_CTRL_FLAG_DISABLED;
+ }
}
if (ctrl->info.flags & UVC_CTRL_FLAG_GET_DEF) {
---
base-commit: c5aa327e10b194884a9c9001a751f6e4703bc3e3
change-id: 20241213-uvc-eaccess-755cc061a360
Best regards,
--
Ricardo Ribalda <ribalda@chromium.org>
^ permalink raw reply [flat|nested] 6+ messages in thread* Re: [PATCH v4] media: uvcvideo: Set V4L2_CTRL_FLAG_DISABLED during queryctrl errors 2025-01-11 9:57 [PATCH v4] media: uvcvideo: Set V4L2_CTRL_FLAG_DISABLED during queryctrl errors Ricardo Ribalda @ 2025-02-23 17:03 ` Laurent Pinchart 2025-02-24 9:26 ` Ricardo Ribalda 0 siblings, 1 reply; 6+ messages in thread From: Laurent Pinchart @ 2025-02-23 17:03 UTC (permalink / raw) To: Ricardo Ribalda Cc: Hans Verkuil, Hans de Goede, Mauro Carvalho Chehab, linux-media, linux-kernel Hi Ricardo, Thank you for the patch. On Sat, Jan 11, 2025 at 09:57:21AM +0000, Ricardo Ribalda wrote: > To implement VIDIOC_QUERYCTRL, we need to know the minimum, maximum, > step and flags of the control. For some of the controls, this involves > querying the actual hardware. > > Some non-compliant cameras produce errors when we query them. Right now, > we populate that error to userspace. When an error happens, the v4l2 > framework does not copy the v4l2_queryctrl struct to userspace. Also, > userspace apps are not ready to handle any other error than -EINVAL. > > One of the main usecases of VIDIOC_QUERYCTRL is enumerating the controls > of a device. This is done using the V4L2_CTRL_FLAG_NEXT_CTRL flag. In > that usecase, a non-compliant control will make it almost impossible to > enumerate all controls of the device. > > A control with an invalid max/min/step/flags is better than non being > able to enumerate the rest of the controls. > > This patch makes VIDIOC_QUERYCTRL return 0 in all the error cases > different than -EINVAL, introduces a warning in dmesg so we can > have a trace of what has happened and sets the V4L2_CTRL_FLAG_DISABLED. > > Signed-off-by: Ricardo Ribalda <ribalda@chromium.org> > --- > Hi 2*Hans and Laurent! > > I came around a device that was listing just a couple of controls when > it should be listing much more. > > Some debugging latter I found that the device was returning -EIO when > all the focal controls were read. > > Lots of good arguments in favor/against this patch in the v1. Please > check! > > Without this patch: > $ v4l2-ctl --list-ctrls > auto_exposure 0x009a0901 (menu) : min=0 max=3 default=3 value=3 (Aperture Priority Mode) > exposure_time_absolute 0x009a0902 (int) : min=50 max=10000 step=1 default=166 value=166 flags=inactive > exposure_dynamic_framerate 0x009a0903 (bool) : default=0 value=0 > region_of_interest_auto_control 0x009a1902 (bitmask): max=0x00000001 default=0x00000001 value=1 > > With this patch: > $ v4l2-ctl --list-ctrls > auto_exposure 0x009a0901 (menu) : min=0 max=3 default=3 value=3 (Aperture Priority Mode) > exposure_time_absolute 0x009a0902 (int) : min=50 max=10000 step=1 default=166 value=166 flags=inactive > exposure_dynamic_framerate 0x009a0903 (bool) : default=0 value=0 > error 5 getting ext_ctrl Focus, Absolute > error 5 getting ext_ctrl Focus, Automatic Continuous > region_of_interest_rectangle 0x009a1901 (unknown): type=107 value=unsupported payload type flags=has-payload > region_of_interest_auto_control 0x009a1902 (bitmask): max=0x00000001 default=0x00000001 value=1 > -- > --- > Changes in v4: > - Display control name (Thanks Hans) > - Link to v3: https://lore.kernel.org/r/20250107-uvc-eaccess-v3-1-99f3335d5133@chromium.org > > Changes in v3: > - Add a retry mechanism during error. This needs to be explained in the commit message, including when/why it helps, and why the retry count is 2. > - Set V4L2_CTRL_FLAG_DISABLED flag. > - Link to v2: https://lore.kernel.org/r/20241219-uvc-eaccess-v2-1-bf6520c8b86d@chromium.org > > Changes in v2: > - Never return error, even if we are not enumerating the controls > - Improve commit message. > - Link to v1: https://lore.kernel.org/r/20241213-uvc-eaccess-v1-1-62e0b4fcc634@chromium.org > --- > drivers/media/usb/uvc/uvc_ctrl.c | 43 ++++++++++++++++++++++++++++++++-------- > 1 file changed, 35 insertions(+), 8 deletions(-) > > diff --git a/drivers/media/usb/uvc/uvc_ctrl.c b/drivers/media/usb/uvc/uvc_ctrl.c > index 4e58476d305e..9d7812e8572d 100644 > --- a/drivers/media/usb/uvc/uvc_ctrl.c > +++ b/drivers/media/usb/uvc/uvc_ctrl.c > @@ -1280,6 +1280,8 @@ static u32 uvc_get_ctrl_bitmap(struct uvc_control *ctrl, > return ~0; > } > > +#define MAX_QUERY_RETRIES 2 > + > static int __uvc_query_v4l2_ctrl(struct uvc_video_chain *chain, > struct uvc_control *ctrl, > struct uvc_control_mapping *mapping, > @@ -1305,19 +1307,44 @@ static int __uvc_query_v4l2_ctrl(struct uvc_video_chain *chain, > __uvc_find_control(ctrl->entity, mapping->master_id, > &master_map, &master_ctrl, 0); > if (master_ctrl && (master_ctrl->info.flags & UVC_CTRL_FLAG_GET_CUR)) { > + unsigned int retries; > s32 val; > - int ret = __uvc_ctrl_get(chain, master_ctrl, master_map, &val); > - if (ret < 0) > - return ret; > + int ret; > > - if (val != mapping->master_manual) > - v4l2_ctrl->flags |= V4L2_CTRL_FLAG_INACTIVE; > + for (retries = 0; retries < MAX_QUERY_RETRIES; retries++) { > + ret = __uvc_ctrl_get(chain, master_ctrl, master_map, > + &val); > + if (ret >= 0) > + break; > + } > + > + if (ret < 0) { > + dev_warn_ratelimited(&chain->dev->udev->dev, > + "UVC non compliance: Error %d querying master control %x (%s)\n", > + ret, master_map->id, > + uvc_map_get_name(master_map)); > + } else if (val != mapping->master_manual) { > + v4l2_ctrl->flags |= V4L2_CTRL_FLAG_INACTIVE; > + } > } > > if (!ctrl->cached) { > - int ret = uvc_ctrl_populate_cache(chain, ctrl); > - if (ret < 0) > - return ret; > + unsigned int retries; > + int ret; > + > + for (retries = 0; retries < MAX_QUERY_RETRIES; retries++) { > + ret = uvc_ctrl_populate_cache(chain, ctrl); > + if (ret >= 0) > + break; > + } > + > + if (ret < 0) { > + dev_warn_ratelimited(&chain->dev->udev->dev, > + "UVC non compliance: Error %d populating cache of control %x (%s)\n", > + ret, mapping->id, > + uvc_map_get_name(mapping)); > + v4l2_ctrl->flags |= V4L2_CTRL_FLAG_DISABLED; Can we make the control permanently disabled ? > + } > } > > if (ctrl->info.flags & UVC_CTRL_FLAG_GET_DEF) { > > --- > base-commit: c5aa327e10b194884a9c9001a751f6e4703bc3e3 > change-id: 20241213-uvc-eaccess-755cc061a360 -- Regards, Laurent Pinchart ^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: [PATCH v4] media: uvcvideo: Set V4L2_CTRL_FLAG_DISABLED during queryctrl errors 2025-02-23 17:03 ` Laurent Pinchart @ 2025-02-24 9:26 ` Ricardo Ribalda 2025-03-03 15:16 ` Laurent Pinchart 0 siblings, 1 reply; 6+ messages in thread From: Ricardo Ribalda @ 2025-02-24 9:26 UTC (permalink / raw) To: Laurent Pinchart Cc: Hans Verkuil, Hans de Goede, Mauro Carvalho Chehab, linux-media, linux-kernel On Sun, 23 Feb 2025 at 18:03, Laurent Pinchart <laurent.pinchart@ideasonboard.com> wrote: > > Hi Ricardo, > > Thank you for the patch. > > On Sat, Jan 11, 2025 at 09:57:21AM +0000, Ricardo Ribalda wrote: > > To implement VIDIOC_QUERYCTRL, we need to know the minimum, maximum, > > step and flags of the control. For some of the controls, this involves > > querying the actual hardware. > > > > Some non-compliant cameras produce errors when we query them. Right now, > > we populate that error to userspace. When an error happens, the v4l2 > > framework does not copy the v4l2_queryctrl struct to userspace. Also, > > userspace apps are not ready to handle any other error than -EINVAL. > > > > One of the main usecases of VIDIOC_QUERYCTRL is enumerating the controls > > of a device. This is done using the V4L2_CTRL_FLAG_NEXT_CTRL flag. In > > that usecase, a non-compliant control will make it almost impossible to > > enumerate all controls of the device. > > > > A control with an invalid max/min/step/flags is better than non being > > able to enumerate the rest of the controls. > > > > This patch makes VIDIOC_QUERYCTRL return 0 in all the error cases > > different than -EINVAL, introduces a warning in dmesg so we can > > have a trace of what has happened and sets the V4L2_CTRL_FLAG_DISABLED. > > > > Signed-off-by: Ricardo Ribalda <ribalda@chromium.org> > > --- > > Hi 2*Hans and Laurent! > > > > I came around a device that was listing just a couple of controls when > > it should be listing much more. > > > > Some debugging latter I found that the device was returning -EIO when > > all the focal controls were read. > > > > Lots of good arguments in favor/against this patch in the v1. Please > > check! > > > > Without this patch: > > $ v4l2-ctl --list-ctrls > > auto_exposure 0x009a0901 (menu) : min=0 max=3 default=3 value=3 (Aperture Priority Mode) > > exposure_time_absolute 0x009a0902 (int) : min=50 max=10000 step=1 default=166 value=166 flags=inactive > > exposure_dynamic_framerate 0x009a0903 (bool) : default=0 value=0 > > region_of_interest_auto_control 0x009a1902 (bitmask): max=0x00000001 default=0x00000001 value=1 > > > > With this patch: > > $ v4l2-ctl --list-ctrls > > auto_exposure 0x009a0901 (menu) : min=0 max=3 default=3 value=3 (Aperture Priority Mode) > > exposure_time_absolute 0x009a0902 (int) : min=50 max=10000 step=1 default=166 value=166 flags=inactive > > exposure_dynamic_framerate 0x009a0903 (bool) : default=0 value=0 > > error 5 getting ext_ctrl Focus, Absolute > > error 5 getting ext_ctrl Focus, Automatic Continuous > > region_of_interest_rectangle 0x009a1901 (unknown): type=107 value=unsupported payload type flags=has-payload > > region_of_interest_auto_control 0x009a1902 (bitmask): max=0x00000001 default=0x00000001 value=1 > > -- > > --- > > Changes in v4: > > - Display control name (Thanks Hans) > > - Link to v3: https://lore.kernel.org/r/20250107-uvc-eaccess-v3-1-99f3335d5133@chromium.org > > > > Changes in v3: > > - Add a retry mechanism during error. > > This needs to be explained in the commit message, including when/why it > helps, and why the retry count is 2. > > > - Set V4L2_CTRL_FLAG_DISABLED flag. > > - Link to v2: https://lore.kernel.org/r/20241219-uvc-eaccess-v2-1-bf6520c8b86d@chromium.org > > > > Changes in v2: > > - Never return error, even if we are not enumerating the controls > > - Improve commit message. > > - Link to v1: https://lore.kernel.org/r/20241213-uvc-eaccess-v1-1-62e0b4fcc634@chromium.org > > --- > > drivers/media/usb/uvc/uvc_ctrl.c | 43 ++++++++++++++++++++++++++++++++-------- > > 1 file changed, 35 insertions(+), 8 deletions(-) > > > > diff --git a/drivers/media/usb/uvc/uvc_ctrl.c b/drivers/media/usb/uvc/uvc_ctrl.c > > index 4e58476d305e..9d7812e8572d 100644 > > --- a/drivers/media/usb/uvc/uvc_ctrl.c > > +++ b/drivers/media/usb/uvc/uvc_ctrl.c > > @@ -1280,6 +1280,8 @@ static u32 uvc_get_ctrl_bitmap(struct uvc_control *ctrl, > > return ~0; > > } > > > > +#define MAX_QUERY_RETRIES 2 > > + > > static int __uvc_query_v4l2_ctrl(struct uvc_video_chain *chain, > > struct uvc_control *ctrl, > > struct uvc_control_mapping *mapping, > > @@ -1305,19 +1307,44 @@ static int __uvc_query_v4l2_ctrl(struct uvc_video_chain *chain, > > __uvc_find_control(ctrl->entity, mapping->master_id, > > &master_map, &master_ctrl, 0); > > if (master_ctrl && (master_ctrl->info.flags & UVC_CTRL_FLAG_GET_CUR)) { > > + unsigned int retries; > > s32 val; > > - int ret = __uvc_ctrl_get(chain, master_ctrl, master_map, &val); > > - if (ret < 0) > > - return ret; > > + int ret; > > > > - if (val != mapping->master_manual) > > - v4l2_ctrl->flags |= V4L2_CTRL_FLAG_INACTIVE; > > + for (retries = 0; retries < MAX_QUERY_RETRIES; retries++) { > > + ret = __uvc_ctrl_get(chain, master_ctrl, master_map, > > + &val); > > + if (ret >= 0) > > + break; > > + } > > + > > + if (ret < 0) { > > + dev_warn_ratelimited(&chain->dev->udev->dev, > > + "UVC non compliance: Error %d querying master control %x (%s)\n", > > + ret, master_map->id, > > + uvc_map_get_name(master_map)); > > + } else if (val != mapping->master_manual) { > > + v4l2_ctrl->flags |= V4L2_CTRL_FLAG_INACTIVE; > > + } > > } > > > > if (!ctrl->cached) { > > - int ret = uvc_ctrl_populate_cache(chain, ctrl); > > - if (ret < 0) > > - return ret; > > + unsigned int retries; > > + int ret; > > + > > + for (retries = 0; retries < MAX_QUERY_RETRIES; retries++) { > > + ret = uvc_ctrl_populate_cache(chain, ctrl); > > + if (ret >= 0) > > + break; > > + } > > + > > + if (ret < 0) { > > + dev_warn_ratelimited(&chain->dev->udev->dev, > > + "UVC non compliance: Error %d populating cache of control %x (%s)\n", > > + ret, mapping->id, > > + uvc_map_get_name(mapping)); > > + v4l2_ctrl->flags |= V4L2_CTRL_FLAG_DISABLED; > > Can we make the control permanently disabled ? I'd rather not. In funky hardware the control might work with the right combination of other controls. > > > + } > > } > > > > if (ctrl->info.flags & UVC_CTRL_FLAG_GET_DEF) { > > > > --- > > base-commit: c5aa327e10b194884a9c9001a751f6e4703bc3e3 > > change-id: 20241213-uvc-eaccess-755cc061a360 > > -- > Regards, > > Laurent Pinchart -- Ricardo Ribalda ^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: [PATCH v4] media: uvcvideo: Set V4L2_CTRL_FLAG_DISABLED during queryctrl errors 2025-02-24 9:26 ` Ricardo Ribalda @ 2025-03-03 15:16 ` Laurent Pinchart 2025-03-03 16:05 ` Ricardo Ribalda 0 siblings, 1 reply; 6+ messages in thread From: Laurent Pinchart @ 2025-03-03 15:16 UTC (permalink / raw) To: Ricardo Ribalda Cc: Hans Verkuil, Hans de Goede, Mauro Carvalho Chehab, linux-media, linux-kernel On Mon, Feb 24, 2025 at 10:26:34AM +0100, Ricardo Ribalda wrote: > On Sun, 23 Feb 2025 at 18:03, Laurent Pinchart wrote: > > On Sat, Jan 11, 2025 at 09:57:21AM +0000, Ricardo Ribalda wrote: > > > To implement VIDIOC_QUERYCTRL, we need to know the minimum, maximum, > > > step and flags of the control. For some of the controls, this involves > > > querying the actual hardware. > > > > > > Some non-compliant cameras produce errors when we query them. Right now, > > > we populate that error to userspace. When an error happens, the v4l2 > > > framework does not copy the v4l2_queryctrl struct to userspace. Also, > > > userspace apps are not ready to handle any other error than -EINVAL. > > > > > > One of the main usecases of VIDIOC_QUERYCTRL is enumerating the controls > > > of a device. This is done using the V4L2_CTRL_FLAG_NEXT_CTRL flag. In > > > that usecase, a non-compliant control will make it almost impossible to > > > enumerate all controls of the device. > > > > > > A control with an invalid max/min/step/flags is better than non being > > > able to enumerate the rest of the controls. > > > > > > This patch makes VIDIOC_QUERYCTRL return 0 in all the error cases > > > different than -EINVAL, introduces a warning in dmesg so we can > > > have a trace of what has happened and sets the V4L2_CTRL_FLAG_DISABLED. > > > > > > Signed-off-by: Ricardo Ribalda <ribalda@chromium.org> > > > --- > > > Hi 2*Hans and Laurent! > > > > > > I came around a device that was listing just a couple of controls when > > > it should be listing much more. > > > > > > Some debugging latter I found that the device was returning -EIO when > > > all the focal controls were read. > > > > > > Lots of good arguments in favor/against this patch in the v1. Please > > > check! > > > > > > Without this patch: > > > $ v4l2-ctl --list-ctrls > > > auto_exposure 0x009a0901 (menu) : min=0 max=3 default=3 value=3 (Aperture Priority Mode) > > > exposure_time_absolute 0x009a0902 (int) : min=50 max=10000 step=1 default=166 value=166 flags=inactive > > > exposure_dynamic_framerate 0x009a0903 (bool) : default=0 value=0 > > > region_of_interest_auto_control 0x009a1902 (bitmask): max=0x00000001 default=0x00000001 value=1 > > > > > > With this patch: > > > $ v4l2-ctl --list-ctrls > > > auto_exposure 0x009a0901 (menu) : min=0 max=3 default=3 value=3 (Aperture Priority Mode) > > > exposure_time_absolute 0x009a0902 (int) : min=50 max=10000 step=1 default=166 value=166 flags=inactive > > > exposure_dynamic_framerate 0x009a0903 (bool) : default=0 value=0 > > > error 5 getting ext_ctrl Focus, Absolute > > > error 5 getting ext_ctrl Focus, Automatic Continuous > > > region_of_interest_rectangle 0x009a1901 (unknown): type=107 value=unsupported payload type flags=has-payload > > > region_of_interest_auto_control 0x009a1902 (bitmask): max=0x00000001 default=0x00000001 value=1 > > > -- > > > --- > > > Changes in v4: > > > - Display control name (Thanks Hans) > > > - Link to v3: https://lore.kernel.org/r/20250107-uvc-eaccess-v3-1-99f3335d5133@chromium.org > > > > > > Changes in v3: > > > - Add a retry mechanism during error. > > > > This needs to be explained in the commit message, including when/why it > > helps, and why the retry count is 2. > > > > > - Set V4L2_CTRL_FLAG_DISABLED flag. > > > - Link to v2: https://lore.kernel.org/r/20241219-uvc-eaccess-v2-1-bf6520c8b86d@chromium.org > > > > > > Changes in v2: > > > - Never return error, even if we are not enumerating the controls > > > - Improve commit message. > > > - Link to v1: https://lore.kernel.org/r/20241213-uvc-eaccess-v1-1-62e0b4fcc634@chromium.org > > > --- > > > drivers/media/usb/uvc/uvc_ctrl.c | 43 ++++++++++++++++++++++++++++++++-------- > > > 1 file changed, 35 insertions(+), 8 deletions(-) > > > > > > diff --git a/drivers/media/usb/uvc/uvc_ctrl.c b/drivers/media/usb/uvc/uvc_ctrl.c > > > index 4e58476d305e..9d7812e8572d 100644 > > > --- a/drivers/media/usb/uvc/uvc_ctrl.c > > > +++ b/drivers/media/usb/uvc/uvc_ctrl.c > > > @@ -1280,6 +1280,8 @@ static u32 uvc_get_ctrl_bitmap(struct uvc_control *ctrl, > > > return ~0; > > > } > > > > > > +#define MAX_QUERY_RETRIES 2 > > > + > > > static int __uvc_query_v4l2_ctrl(struct uvc_video_chain *chain, > > > struct uvc_control *ctrl, > > > struct uvc_control_mapping *mapping, > > > @@ -1305,19 +1307,44 @@ static int __uvc_query_v4l2_ctrl(struct uvc_video_chain *chain, > > > __uvc_find_control(ctrl->entity, mapping->master_id, > > > &master_map, &master_ctrl, 0); > > > if (master_ctrl && (master_ctrl->info.flags & UVC_CTRL_FLAG_GET_CUR)) { > > > + unsigned int retries; > > > s32 val; > > > - int ret = __uvc_ctrl_get(chain, master_ctrl, master_map, &val); > > > - if (ret < 0) > > > - return ret; > > > + int ret; > > > > > > - if (val != mapping->master_manual) > > > - v4l2_ctrl->flags |= V4L2_CTRL_FLAG_INACTIVE; > > > + for (retries = 0; retries < MAX_QUERY_RETRIES; retries++) { > > > + ret = __uvc_ctrl_get(chain, master_ctrl, master_map, > > > + &val); > > > + if (ret >= 0) > > > + break; > > > + } > > > + > > > + if (ret < 0) { > > > + dev_warn_ratelimited(&chain->dev->udev->dev, > > > + "UVC non compliance: Error %d querying master control %x (%s)\n", > > > + ret, master_map->id, > > > + uvc_map_get_name(master_map)); > > > + } else if (val != mapping->master_manual) { > > > + v4l2_ctrl->flags |= V4L2_CTRL_FLAG_INACTIVE; > > > + } > > > } > > > > > > if (!ctrl->cached) { > > > - int ret = uvc_ctrl_populate_cache(chain, ctrl); > > > - if (ret < 0) > > > - return ret; > > > + unsigned int retries; > > > + int ret; > > > + > > > + for (retries = 0; retries < MAX_QUERY_RETRIES; retries++) { > > > + ret = uvc_ctrl_populate_cache(chain, ctrl); > > > + if (ret >= 0) > > > + break; > > > + } > > > + > > > + if (ret < 0) { > > > + dev_warn_ratelimited(&chain->dev->udev->dev, > > > + "UVC non compliance: Error %d populating cache of control %x (%s)\n", > > > + ret, mapping->id, > > > + uvc_map_get_name(mapping)); > > > + v4l2_ctrl->flags |= V4L2_CTRL_FLAG_DISABLED; > > > > Can we make the control permanently disabled ? > > I'd rather not. In funky hardware the control might work with the > right combination of other controls. That makes the behaviour random and therefore very confusing for userspace. All of a sudden a control will start being available, even if it was marked as disabled during enumeration. > > > + } > > > } > > > > > > if (ctrl->info.flags & UVC_CTRL_FLAG_GET_DEF) { > > > > > > --- > > > base-commit: c5aa327e10b194884a9c9001a751f6e4703bc3e3 > > > change-id: 20241213-uvc-eaccess-755cc061a360 -- Regards, Laurent Pinchart ^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: [PATCH v4] media: uvcvideo: Set V4L2_CTRL_FLAG_DISABLED during queryctrl errors 2025-03-03 15:16 ` Laurent Pinchart @ 2025-03-03 16:05 ` Ricardo Ribalda 2025-03-03 16:16 ` Hans Verkuil 0 siblings, 1 reply; 6+ messages in thread From: Ricardo Ribalda @ 2025-03-03 16:05 UTC (permalink / raw) To: Laurent Pinchart, Hans Verkuil Cc: Hans de Goede, Mauro Carvalho Chehab, linux-media, linux-kernel On Mon, 3 Mar 2025 at 16:16, Laurent Pinchart <laurent.pinchart@ideasonboard.com> wrote: > > On Mon, Feb 24, 2025 at 10:26:34AM +0100, Ricardo Ribalda wrote: > > On Sun, 23 Feb 2025 at 18:03, Laurent Pinchart wrote: > > > On Sat, Jan 11, 2025 at 09:57:21AM +0000, Ricardo Ribalda wrote: > > > > To implement VIDIOC_QUERYCTRL, we need to know the minimum, maximum, > > > > step and flags of the control. For some of the controls, this involves > > > > querying the actual hardware. > > > > > > > > Some non-compliant cameras produce errors when we query them. Right now, > > > > we populate that error to userspace. When an error happens, the v4l2 > > > > framework does not copy the v4l2_queryctrl struct to userspace. Also, > > > > userspace apps are not ready to handle any other error than -EINVAL. > > > > > > > > One of the main usecases of VIDIOC_QUERYCTRL is enumerating the controls > > > > of a device. This is done using the V4L2_CTRL_FLAG_NEXT_CTRL flag. In > > > > that usecase, a non-compliant control will make it almost impossible to > > > > enumerate all controls of the device. > > > > > > > > A control with an invalid max/min/step/flags is better than non being > > > > able to enumerate the rest of the controls. > > > > > > > > This patch makes VIDIOC_QUERYCTRL return 0 in all the error cases > > > > different than -EINVAL, introduces a warning in dmesg so we can > > > > have a trace of what has happened and sets the V4L2_CTRL_FLAG_DISABLED. > > > > > > > > Signed-off-by: Ricardo Ribalda <ribalda@chromium.org> > > > > --- > > > > Hi 2*Hans and Laurent! > > > > > > > > I came around a device that was listing just a couple of controls when > > > > it should be listing much more. > > > > > > > > Some debugging latter I found that the device was returning -EIO when > > > > all the focal controls were read. > > > > > > > > Lots of good arguments in favor/against this patch in the v1. Please > > > > check! > > > > > > > > Without this patch: > > > > $ v4l2-ctl --list-ctrls > > > > auto_exposure 0x009a0901 (menu) : min=0 max=3 default=3 value=3 (Aperture Priority Mode) > > > > exposure_time_absolute 0x009a0902 (int) : min=50 max=10000 step=1 default=166 value=166 flags=inactive > > > > exposure_dynamic_framerate 0x009a0903 (bool) : default=0 value=0 > > > > region_of_interest_auto_control 0x009a1902 (bitmask): max=0x00000001 default=0x00000001 value=1 > > > > > > > > With this patch: > > > > $ v4l2-ctl --list-ctrls > > > > auto_exposure 0x009a0901 (menu) : min=0 max=3 default=3 value=3 (Aperture Priority Mode) > > > > exposure_time_absolute 0x009a0902 (int) : min=50 max=10000 step=1 default=166 value=166 flags=inactive > > > > exposure_dynamic_framerate 0x009a0903 (bool) : default=0 value=0 > > > > error 5 getting ext_ctrl Focus, Absolute > > > > error 5 getting ext_ctrl Focus, Automatic Continuous > > > > region_of_interest_rectangle 0x009a1901 (unknown): type=107 value=unsupported payload type flags=has-payload > > > > region_of_interest_auto_control 0x009a1902 (bitmask): max=0x00000001 default=0x00000001 value=1 > > > > -- > > > > --- > > > > Changes in v4: > > > > - Display control name (Thanks Hans) > > > > - Link to v3: https://lore.kernel.org/r/20250107-uvc-eaccess-v3-1-99f3335d5133@chromium.org > > > > > > > > Changes in v3: > > > > - Add a retry mechanism during error. > > > > > > This needs to be explained in the commit message, including when/why it > > > helps, and why the retry count is 2. > > > > > > > - Set V4L2_CTRL_FLAG_DISABLED flag. > > > > - Link to v2: https://lore.kernel.org/r/20241219-uvc-eaccess-v2-1-bf6520c8b86d@chromium.org > > > > > > > > Changes in v2: > > > > - Never return error, even if we are not enumerating the controls > > > > - Improve commit message. > > > > - Link to v1: https://lore.kernel.org/r/20241213-uvc-eaccess-v1-1-62e0b4fcc634@chromium.org > > > > --- > > > > drivers/media/usb/uvc/uvc_ctrl.c | 43 ++++++++++++++++++++++++++++++++-------- > > > > 1 file changed, 35 insertions(+), 8 deletions(-) > > > > > > > > diff --git a/drivers/media/usb/uvc/uvc_ctrl.c b/drivers/media/usb/uvc/uvc_ctrl.c > > > > index 4e58476d305e..9d7812e8572d 100644 > > > > --- a/drivers/media/usb/uvc/uvc_ctrl.c > > > > +++ b/drivers/media/usb/uvc/uvc_ctrl.c > > > > @@ -1280,6 +1280,8 @@ static u32 uvc_get_ctrl_bitmap(struct uvc_control *ctrl, > > > > return ~0; > > > > } > > > > > > > > +#define MAX_QUERY_RETRIES 2 > > > > + > > > > static int __uvc_query_v4l2_ctrl(struct uvc_video_chain *chain, > > > > struct uvc_control *ctrl, > > > > struct uvc_control_mapping *mapping, > > > > @@ -1305,19 +1307,44 @@ static int __uvc_query_v4l2_ctrl(struct uvc_video_chain *chain, > > > > __uvc_find_control(ctrl->entity, mapping->master_id, > > > > &master_map, &master_ctrl, 0); > > > > if (master_ctrl && (master_ctrl->info.flags & UVC_CTRL_FLAG_GET_CUR)) { > > > > + unsigned int retries; > > > > s32 val; > > > > - int ret = __uvc_ctrl_get(chain, master_ctrl, master_map, &val); > > > > - if (ret < 0) > > > > - return ret; > > > > + int ret; > > > > > > > > - if (val != mapping->master_manual) > > > > - v4l2_ctrl->flags |= V4L2_CTRL_FLAG_INACTIVE; > > > > + for (retries = 0; retries < MAX_QUERY_RETRIES; retries++) { > > > > + ret = __uvc_ctrl_get(chain, master_ctrl, master_map, > > > > + &val); > > > > + if (ret >= 0) > > > > + break; > > > > + } > > > > + > > > > + if (ret < 0) { > > > > + dev_warn_ratelimited(&chain->dev->udev->dev, > > > > + "UVC non compliance: Error %d querying master control %x (%s)\n", > > > > + ret, master_map->id, > > > > + uvc_map_get_name(master_map)); > > > > + } else if (val != mapping->master_manual) { > > > > + v4l2_ctrl->flags |= V4L2_CTRL_FLAG_INACTIVE; > > > > + } > > > > } > > > > > > > > if (!ctrl->cached) { > > > > - int ret = uvc_ctrl_populate_cache(chain, ctrl); > > > > - if (ret < 0) > > > > - return ret; > > > > + unsigned int retries; > > > > + int ret; > > > > + > > > > + for (retries = 0; retries < MAX_QUERY_RETRIES; retries++) { > > > > + ret = uvc_ctrl_populate_cache(chain, ctrl); > > > > + if (ret >= 0) > > > > + break; > > > > + } > > > > + > > > > + if (ret < 0) { > > > > + dev_warn_ratelimited(&chain->dev->udev->dev, > > > > + "UVC non compliance: Error %d populating cache of control %x (%s)\n", > > > > + ret, mapping->id, > > > > + uvc_map_get_name(mapping)); > > > > + v4l2_ctrl->flags |= V4L2_CTRL_FLAG_DISABLED; > > > > > > Can we make the control permanently disabled ? > > > > I'd rather not. In funky hardware the control might work with the > > right combination of other controls. > > That makes the behaviour random and therefore very confusing for > userspace. All of a sudden a control will start being available, even if > it was marked as disabled during enumeration. Random weird hardware will have random behaviour. I think this is kind of expected. Also there are probably lots of cameras in the field that cannot enumerate properly but are used by custom apps. We are going to break userspace if we enforce this. Hans V. What do you think? > > > > > + } > > > > } > > > > > > > > if (ctrl->info.flags & UVC_CTRL_FLAG_GET_DEF) { > > > > > > > > --- > > > > base-commit: c5aa327e10b194884a9c9001a751f6e4703bc3e3 > > > > change-id: 20241213-uvc-eaccess-755cc061a360 > > -- > Regards, > > Laurent Pinchart -- Ricardo Ribalda ^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: [PATCH v4] media: uvcvideo: Set V4L2_CTRL_FLAG_DISABLED during queryctrl errors 2025-03-03 16:05 ` Ricardo Ribalda @ 2025-03-03 16:16 ` Hans Verkuil 0 siblings, 0 replies; 6+ messages in thread From: Hans Verkuil @ 2025-03-03 16:16 UTC (permalink / raw) To: Ricardo Ribalda, Laurent Pinchart Cc: Hans de Goede, Mauro Carvalho Chehab, linux-media, linux-kernel On 03/03/2025 17:05, Ricardo Ribalda wrote: > On Mon, 3 Mar 2025 at 16:16, Laurent Pinchart > <laurent.pinchart@ideasonboard.com> wrote: >> >> On Mon, Feb 24, 2025 at 10:26:34AM +0100, Ricardo Ribalda wrote: >>> On Sun, 23 Feb 2025 at 18:03, Laurent Pinchart wrote: >>>> On Sat, Jan 11, 2025 at 09:57:21AM +0000, Ricardo Ribalda wrote: >>>>> To implement VIDIOC_QUERYCTRL, we need to know the minimum, maximum, >>>>> step and flags of the control. For some of the controls, this involves >>>>> querying the actual hardware. >>>>> >>>>> Some non-compliant cameras produce errors when we query them. Right now, >>>>> we populate that error to userspace. When an error happens, the v4l2 >>>>> framework does not copy the v4l2_queryctrl struct to userspace. Also, >>>>> userspace apps are not ready to handle any other error than -EINVAL. >>>>> >>>>> One of the main usecases of VIDIOC_QUERYCTRL is enumerating the controls >>>>> of a device. This is done using the V4L2_CTRL_FLAG_NEXT_CTRL flag. In >>>>> that usecase, a non-compliant control will make it almost impossible to >>>>> enumerate all controls of the device. >>>>> >>>>> A control with an invalid max/min/step/flags is better than non being >>>>> able to enumerate the rest of the controls. >>>>> >>>>> This patch makes VIDIOC_QUERYCTRL return 0 in all the error cases >>>>> different than -EINVAL, introduces a warning in dmesg so we can >>>>> have a trace of what has happened and sets the V4L2_CTRL_FLAG_DISABLED. >>>>> >>>>> Signed-off-by: Ricardo Ribalda <ribalda@chromium.org> >>>>> --- >>>>> Hi 2*Hans and Laurent! >>>>> >>>>> I came around a device that was listing just a couple of controls when >>>>> it should be listing much more. >>>>> >>>>> Some debugging latter I found that the device was returning -EIO when >>>>> all the focal controls were read. >>>>> >>>>> Lots of good arguments in favor/against this patch in the v1. Please >>>>> check! >>>>> >>>>> Without this patch: >>>>> $ v4l2-ctl --list-ctrls >>>>> auto_exposure 0x009a0901 (menu) : min=0 max=3 default=3 value=3 (Aperture Priority Mode) >>>>> exposure_time_absolute 0x009a0902 (int) : min=50 max=10000 step=1 default=166 value=166 flags=inactive >>>>> exposure_dynamic_framerate 0x009a0903 (bool) : default=0 value=0 >>>>> region_of_interest_auto_control 0x009a1902 (bitmask): max=0x00000001 default=0x00000001 value=1 >>>>> >>>>> With this patch: >>>>> $ v4l2-ctl --list-ctrls >>>>> auto_exposure 0x009a0901 (menu) : min=0 max=3 default=3 value=3 (Aperture Priority Mode) >>>>> exposure_time_absolute 0x009a0902 (int) : min=50 max=10000 step=1 default=166 value=166 flags=inactive >>>>> exposure_dynamic_framerate 0x009a0903 (bool) : default=0 value=0 >>>>> error 5 getting ext_ctrl Focus, Absolute >>>>> error 5 getting ext_ctrl Focus, Automatic Continuous >>>>> region_of_interest_rectangle 0x009a1901 (unknown): type=107 value=unsupported payload type flags=has-payload >>>>> region_of_interest_auto_control 0x009a1902 (bitmask): max=0x00000001 default=0x00000001 value=1 >>>>> -- >>>>> --- >>>>> Changes in v4: >>>>> - Display control name (Thanks Hans) >>>>> - Link to v3: https://lore.kernel.org/r/20250107-uvc-eaccess-v3-1-99f3335d5133@chromium.org >>>>> >>>>> Changes in v3: >>>>> - Add a retry mechanism during error. >>>> >>>> This needs to be explained in the commit message, including when/why it >>>> helps, and why the retry count is 2. >>>> >>>>> - Set V4L2_CTRL_FLAG_DISABLED flag. >>>>> - Link to v2: https://lore.kernel.org/r/20241219-uvc-eaccess-v2-1-bf6520c8b86d@chromium.org >>>>> >>>>> Changes in v2: >>>>> - Never return error, even if we are not enumerating the controls >>>>> - Improve commit message. >>>>> - Link to v1: https://lore.kernel.org/r/20241213-uvc-eaccess-v1-1-62e0b4fcc634@chromium.org >>>>> --- >>>>> drivers/media/usb/uvc/uvc_ctrl.c | 43 ++++++++++++++++++++++++++++++++-------- >>>>> 1 file changed, 35 insertions(+), 8 deletions(-) >>>>> >>>>> diff --git a/drivers/media/usb/uvc/uvc_ctrl.c b/drivers/media/usb/uvc/uvc_ctrl.c >>>>> index 4e58476d305e..9d7812e8572d 100644 >>>>> --- a/drivers/media/usb/uvc/uvc_ctrl.c >>>>> +++ b/drivers/media/usb/uvc/uvc_ctrl.c >>>>> @@ -1280,6 +1280,8 @@ static u32 uvc_get_ctrl_bitmap(struct uvc_control *ctrl, >>>>> return ~0; >>>>> } >>>>> >>>>> +#define MAX_QUERY_RETRIES 2 >>>>> + >>>>> static int __uvc_query_v4l2_ctrl(struct uvc_video_chain *chain, >>>>> struct uvc_control *ctrl, >>>>> struct uvc_control_mapping *mapping, >>>>> @@ -1305,19 +1307,44 @@ static int __uvc_query_v4l2_ctrl(struct uvc_video_chain *chain, >>>>> __uvc_find_control(ctrl->entity, mapping->master_id, >>>>> &master_map, &master_ctrl, 0); >>>>> if (master_ctrl && (master_ctrl->info.flags & UVC_CTRL_FLAG_GET_CUR)) { >>>>> + unsigned int retries; >>>>> s32 val; >>>>> - int ret = __uvc_ctrl_get(chain, master_ctrl, master_map, &val); >>>>> - if (ret < 0) >>>>> - return ret; >>>>> + int ret; >>>>> >>>>> - if (val != mapping->master_manual) >>>>> - v4l2_ctrl->flags |= V4L2_CTRL_FLAG_INACTIVE; >>>>> + for (retries = 0; retries < MAX_QUERY_RETRIES; retries++) { >>>>> + ret = __uvc_ctrl_get(chain, master_ctrl, master_map, >>>>> + &val); >>>>> + if (ret >= 0) >>>>> + break; >>>>> + } >>>>> + >>>>> + if (ret < 0) { >>>>> + dev_warn_ratelimited(&chain->dev->udev->dev, >>>>> + "UVC non compliance: Error %d querying master control %x (%s)\n", >>>>> + ret, master_map->id, >>>>> + uvc_map_get_name(master_map)); >>>>> + } else if (val != mapping->master_manual) { >>>>> + v4l2_ctrl->flags |= V4L2_CTRL_FLAG_INACTIVE; >>>>> + } >>>>> } >>>>> >>>>> if (!ctrl->cached) { >>>>> - int ret = uvc_ctrl_populate_cache(chain, ctrl); >>>>> - if (ret < 0) >>>>> - return ret; >>>>> + unsigned int retries; >>>>> + int ret; >>>>> + >>>>> + for (retries = 0; retries < MAX_QUERY_RETRIES; retries++) { >>>>> + ret = uvc_ctrl_populate_cache(chain, ctrl); >>>>> + if (ret >= 0) >>>>> + break; >>>>> + } >>>>> + >>>>> + if (ret < 0) { >>>>> + dev_warn_ratelimited(&chain->dev->udev->dev, >>>>> + "UVC non compliance: Error %d populating cache of control %x (%s)\n", >>>>> + ret, mapping->id, >>>>> + uvc_map_get_name(mapping)); >>>>> + v4l2_ctrl->flags |= V4L2_CTRL_FLAG_DISABLED; >>>> >>>> Can we make the control permanently disabled ? >>> >>> I'd rather not. In funky hardware the control might work with the >>> right combination of other controls. >> >> That makes the behaviour random and therefore very confusing for >> userspace. All of a sudden a control will start being available, even if >> it was marked as disabled during enumeration. > > Random weird hardware will have random behaviour. I think this is kind > of expected. > > Also there are probably lots of cameras in the field that cannot > enumerate properly but are used by custom apps. We are going to break > userspace if we enforce this. > > Hans V. What do you think? I agree with Laurent here. If this sometimes works, and sometimes it doesn't, then what is an application going to do with that? I would start with just permanently disabling this. If it turns out that for some hardware this works with some magic combination of other controls values, then that feels more like a quirk to me. One note, though: >>>>> + dev_warn_ratelimited(&chain->dev->udev->dev, >>>>> + "UVC non compliance: Error %d populating cache of control %x (%s)\n", >>>>> + ret, mapping->id, >>>>> + uvc_map_get_name(mapping)); >>>>> + v4l2_ctrl->flags |= V4L2_CTRL_FLAG_DISABLED; That warning is too cryptic. You want to clearly state in the kernel log that this specific control is disabled due to UVC non compliance. E.g.: "UVC non-compliance: permanently disabling control %x (%s) due to error %d\n", Regards, Hans > >> >>>>> + } >>>>> } >>>>> >>>>> if (ctrl->info.flags & UVC_CTRL_FLAG_GET_DEF) { >>>>> >>>>> --- >>>>> base-commit: c5aa327e10b194884a9c9001a751f6e4703bc3e3 >>>>> change-id: 20241213-uvc-eaccess-755cc061a360 >> >> -- >> Regards, >> >> Laurent Pinchart > > > ^ permalink raw reply [flat|nested] 6+ messages in thread
end of thread, other threads:[~2025-03-03 16:16 UTC | newest] Thread overview: 6+ messages (download: mbox.gz / follow: Atom feed) -- links below jump to the message on this page -- 2025-01-11 9:57 [PATCH v4] media: uvcvideo: Set V4L2_CTRL_FLAG_DISABLED during queryctrl errors Ricardo Ribalda 2025-02-23 17:03 ` Laurent Pinchart 2025-02-24 9:26 ` Ricardo Ribalda 2025-03-03 15:16 ` Laurent Pinchart 2025-03-03 16:05 ` Ricardo Ribalda 2025-03-03 16:16 ` Hans Verkuil
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