media: uvcvideo: Fix custom control mapping probing

Custom control mapping introduced a bug, where the filter function was
applied to every single control.

Fix it so it is only applied to the matching controls.

The following dmesg errors during probe are now fixed:

usb 1-5: Found UVC 1.00 device Integrated_Webcam_HD (0c45:670c)
usb 1-5: Failed to query (GET_CUR) UVC control 2 on unit 2: -75 (exp. 1).
usb 1-5: Failed to query (GET_CUR) UVC control 3 on unit 2: -75 (exp. 1).
usb 1-5: Failed to query (GET_CUR) UVC control 6 on unit 2: -75 (exp. 1).
usb 1-5: Failed to query (GET_CUR) UVC control 7 on unit 2: -75 (exp. 1).
usb 1-5: Failed to query (GET_CUR) UVC control 8 on unit 2: -75 (exp. 1).
usb 1-5: Failed to query (GET_CUR) UVC control 9 on unit 2: -75 (exp. 1).
usb 1-5: Failed to query (GET_CUR) UVC control 10 on unit 2: -75 (exp. 1).

Reported-by: Paul Menzel <[email protected]>
Closes: https://lore.kernel.org/linux-media/[email protected]/T/#t
Cc: [email protected]
Fixes: 8f4362a ("media: uvcvideo: Allow custom control mapping")
Signed-off-by: Ricardo Ribalda <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Tested-by: Paul Menzel <[email protected]>
Reviewed-by: Laurent Pinchart <[email protected]>
Signed-off-by: Laurent Pinchart <[email protected]>

Author: ribalda

drivers/media/usb/uvc/uvc_ctrl.c

@@ -2680,16 +2680,18 @@ static void uvc_ctrl_init_ctrl(struct uvc_video_chain *chain,
 	for (i = 0; i < ARRAY_SIZE(uvc_ctrl_mappings); ++i) {
 		const struct uvc_control_mapping *mapping = &uvc_ctrl_mappings[i];
 
+		if (!uvc_entity_match_guid(ctrl->entity, mapping->entity) ||
+		    ctrl->info.selector != mapping->selector)
+			continue;
+
 		/* Let the device provide a custom mapping. */
 		if (mapping->filter_mapping) {
 			mapping = mapping->filter_mapping(chain, ctrl);
 			if (!mapping)
 				continue;
 		}
 
-		if (uvc_entity_match_guid(ctrl->entity, mapping->entity) &&
-		    ctrl->info.selector == mapping->selector)
-			__uvc_ctrl_add_mapping(chain, ctrl, mapping);
+		__uvc_ctrl_add_mapping(chain, ctrl, mapping);
 	}
 }