On Mon Aug 18 20:15:38 2025 +0000, Ricardo Ribalda wrote:
> The function uvc_ctrl_init_ctrl() is called for every control for every
> entity, but it exits early if the entity is a extension unit. The comment
> claims that this is done to avoid querying XU controls during probe.
>
> We only query a control if its entity GUIDs and index matches the
> uvc_ctrls list. There are only controls for the following GUIDs:
> UVC_GUID_UVC_PROCESSING, UVC_GUID_UVC_CAMERA and
> UVC_GUID_EXT_GPIO_CONTROLLER.
>
> In other words, XU controls will not be queried even without this
> condition.
>
> In future patches we want to add ChromeOS XU controls that need to the
> initialized. We will make sure that all cameras with ChromeOS XU can
> be queried at probe time.
>
> Signed-off-by: Ricardo Ribalda <[email protected]>
> Reviewed-by: Hans de Goede <[email protected]>
> Signed-off-by: Hans de Goede <[email protected]>
> Reviewed-by: Laurent Pinchart <[email protected]>
> Signed-off-by: Laurent Pinchart <[email protected]>
> Signed-off-by: Hans Verkuil <[email protected]>
Patch committed.
Thanks,
Hans Verkuil
drivers/media/usb/uvc/uvc_ctrl.c | 9 ---------
1 file changed, 9 deletions(-)
---
diff --git a/drivers/media/usb/uvc/uvc_ctrl.c b/drivers/media/usb/uvc/uvc_ctrl.c
index 535f729086e5..277209ee40c1 100644
--- a/drivers/media/usb/uvc/uvc_ctrl.c
+++ b/drivers/media/usb/uvc/uvc_ctrl.c
@@ -3181,15 +3181,6 @@ static void uvc_ctrl_init_ctrl(struct uvc_video_chain
*chain,
{
unsigned int i;
- /*
- * XU controls initialization requires querying the device for control
- * information. As some buggy UVC devices will crash when queried
- * repeatedly in a tight loop, delay XU controls initialization until
- * first use.
- */
- if (UVC_ENTITY_TYPE(ctrl->entity) == UVC_VC_EXTENSION_UNIT)
- return;
-
for (i = 0; i < ARRAY_SIZE(uvc_ctrls); ++i) {
const struct uvc_control_info *info = &uvc_ctrls[i];
