Hi Hans,
Thank you for the patch.
On Fri, Jul 24, 2020 at 01:48:23PM +0200, Hans de Goede wrote:
> uvc_ctrl_add_info() calls uvc_ctrl_get_flags() which will override
> the fixed-up flags set by uvc_ctrl_fixup_xu_info().
>
> This commit fixes this by adding a is_xu argument to uvc_ctrl_add_info()
> and skipping the uvc_ctrl_get_flags() call for xu ctrls.
>
> Note that the xu path has already called uvc_ctrl_get_flags() from
> uvc_ctrl_fill_xu_info() before calling uvc_ctrl_add_info().
>
> This fixes the xu motor controls not working properly on a Logitech
> 046d:08cc, and presumably also on the other Logitech models which have
> a quirk for this in the uvc_ctrl_fixup_xu_info() function.
>
> Cc: stable@xxxxxxxxxxxxxxx
> Signed-off-by: Hans de Goede <hdegoede@xxxxxxxxxx>
> ---
> drivers/media/usb/uvc/uvc_ctrl.c | 11 ++++++-----
> 1 file changed, 6 insertions(+), 5 deletions(-)
>
> diff --git a/drivers/media/usb/uvc/uvc_ctrl.c b/drivers/media/usb/uvc/uvc_ctrl.c
> index e399b9fad757..4bdea5814d6a 100644
> --- a/drivers/media/usb/uvc/uvc_ctrl.c
> +++ b/drivers/media/usb/uvc/uvc_ctrl.c
> @@ -1815,7 +1815,7 @@ static int uvc_ctrl_fill_xu_info(struct uvc_device *dev,
> }
>
> static int uvc_ctrl_add_info(struct uvc_device *dev, struct uvc_control *ctrl,
> - const struct uvc_control_info *info);
> + const struct uvc_control_info *info, bool is_xu);
>
> static int uvc_ctrl_init_xu_ctrl(struct uvc_device *dev,
> struct uvc_control *ctrl)
> @@ -1830,7 +1830,7 @@ static int uvc_ctrl_init_xu_ctrl(struct uvc_device *dev,
> if (ret < 0)
> return ret;
>
> - ret = uvc_ctrl_add_info(dev, ctrl, &info);
> + ret = uvc_ctrl_add_info(dev, ctrl, &info, true);
> if (ret < 0)
> uvc_trace(UVC_TRACE_CONTROL, "Failed to initialize control "
> "%pUl/%u on device %s entity %u\n", info.entity,
> @@ -2009,7 +2009,7 @@ int uvc_ctrl_restore_values(struct uvc_device *dev)
> * Add control information to a given control.
> */
> static int uvc_ctrl_add_info(struct uvc_device *dev, struct uvc_control *ctrl,
> - const struct uvc_control_info *info)
> + const struct uvc_control_info *info, bool is_xu)
> {
> int ret = 0;
>
> @@ -2029,7 +2029,8 @@ static int uvc_ctrl_add_info(struct uvc_device *dev, struct uvc_control *ctrl,
> * default flag values from the uvc_ctrl array when the device doesn't
> * properly implement GET_INFO on standard controls.
> */
> - uvc_ctrl_get_flags(dev, ctrl, &ctrl->info);
> + if (!is_xu)
> + uvc_ctrl_get_flags(dev, ctrl, &ctrl->info);
Would it make sense to instead move this line (and the above comment) to
uvc_ctrl_init_ctrl(), right after the uvc_ctrl_add_info() call ? If you
would prefer keeping it here, I think is_xu should be renamed to
update_flags (with the true/false values switched) to make it clearer.
It would then also add a comment to uvc_ctrl_init_xu_ctrl() right before
the call to uvc_ctrl_add_info() to state that we don't update flags to
avoid overwriting the value set by uvc_ctrl_fixup_xu_info() in
uvc_ctrl_fill_xu_info().
What's your preference ?
>
> ctrl->initialized = 1;
>
> @@ -2252,7 +2253,7 @@ static void uvc_ctrl_init_ctrl(struct uvc_device *dev, struct uvc_control *ctrl)
> for (; info < iend; ++info) {
> if (uvc_entity_match_guid(ctrl->entity, info->entity) &&
> ctrl->index == info->index) {
> - uvc_ctrl_add_info(dev, ctrl, info);
> + uvc_ctrl_add_info(dev, ctrl, info, false);
> break;
> }
> }
--
Regards,
Laurent Pinchart
