V4L/DVB: uvcvideo: Make button controls work properly
According to the v4l2 spec, writing any value to a button control should
result in the action belonging to the button control being triggered.
UVC cams however want to see a 1 written, this patch fixes this by
overriding whatever value user space passed in with -1 (0xffffffff) when
the control is a button control.
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>
diff --git a/drivers/media/video/uvc/uvc_ctrl.c b/drivers/media/video/uvc/uvc_ctrl.c
index fcfcfbc..4e6d484 100644
--- a/drivers/media/video/uvc/uvc_ctrl.c
+++ b/drivers/media/video/uvc/uvc_ctrl.c
@@ -698,6 +698,14 @@
int offset = mapping->offset;
__u8 mask;
+ /* According to the v4l2 spec, writing any value to a button control
+ * should result in the action belonging to the button control being
+ * triggered. UVC devices however want to see a 1 written -> override
+ * value.
+ */
+ if (mapping->v4l2_type == V4L2_CTRL_TYPE_BUTTON)
+ value = -1;
+
data += offset / 8;
offset &= 7;