[media] uvcvideo: Send control change events for slave ctrls when the master changes

This allows v4l2 control UI-s to update the inactive state (ie grey-ing
out of controls) for slave controls when the master control changes.

[Use __uvc_find_control() to find slave controls, as they're always
located in the same entity as the corresponding master control]

Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.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 ae7371f3a39ec1460abf064ff3a03335aaa66e81..03212c703330e6e3a6629b548859d7c79f8afbd3 100644 (file)
--- a/drivers/media/video/uvc/uvc_ctrl.c
+++ b/drivers/media/video/uvc/uvc_ctrl.c
@@ -1177,22 +1177,76 @@ static void uvc_ctrl_send_event(struct uvc_fh *handle,
 
        list_for_each_entry(sev, &mapping->ev_subs, node) {
                if (sev->fh && (sev->fh != &handle->vfh ||
-                   (sev->flags & V4L2_EVENT_SUB_FL_ALLOW_FEEDBACK)))
+                   (sev->flags & V4L2_EVENT_SUB_FL_ALLOW_FEEDBACK) ||
+                   (changes & V4L2_EVENT_CTRL_CH_FLAGS)))
                        v4l2_event_queue_fh(sev->fh, &ev);
        }
 }
 
+static void uvc_ctrl_send_slave_event(struct uvc_fh *handle,
+       struct uvc_control *master, u32 slave_id,
+       const struct v4l2_ext_control *xctrls, unsigned int xctrls_count)
+{
+       struct uvc_control_mapping *mapping = NULL;
+       struct uvc_control *ctrl = NULL;
+       u32 changes = V4L2_EVENT_CTRL_CH_FLAGS;
+       unsigned int i;
+       s32 val = 0;
+
+       /*
+        * We can skip sending an event for the slave if the slave
+        * is being modified in the same transaction.
+        */
+       for (i = 0; i < xctrls_count; i++) {
+               if (xctrls[i].id == slave_id)
+                       return;
+       }
+
+       __uvc_find_control(master->entity, slave_id, &mapping, &ctrl, 0);
+       if (ctrl == NULL)
+               return;
+
+       if (__uvc_ctrl_get(handle->chain, ctrl, mapping, &val) == 0)
+               changes |= V4L2_EVENT_CTRL_CH_VALUE;
+
+       uvc_ctrl_send_event(handle, ctrl, mapping, val, changes);
+}
+
 static void uvc_ctrl_send_events(struct uvc_fh *handle,
        const struct v4l2_ext_control *xctrls, unsigned int xctrls_count)
 {
        struct uvc_control_mapping *mapping;
        struct uvc_control *ctrl;
+       u32 changes = V4L2_EVENT_CTRL_CH_VALUE;
        unsigned int i;
+       unsigned int j;
 
        for (i = 0; i < xctrls_count; ++i) {
                ctrl = uvc_find_control(handle->chain, xctrls[i].id, &mapping);
+
+               for (j = 0; j < ARRAY_SIZE(mapping->slave_ids); ++j) {
+                       if (!mapping->slave_ids[j])
+                               break;
+                       uvc_ctrl_send_slave_event(handle, ctrl,
+                                                 mapping->slave_ids[j],
+                                                 xctrls, xctrls_count);
+               }
+
+               /*
+                * If the master is being modified in the same transaction
+                * flags may change too.
+                */
+               if (mapping->master_id) {
+                       for (j = 0; j < xctrls_count; j++) {
+                               if (xctrls[j].id == mapping->master_id) {
+                                       changes |= V4L2_EVENT_CTRL_CH_FLAGS;
+                                       break;
+                               }
+                       }
+               }
+
                uvc_ctrl_send_event(handle, ctrl, mapping, xctrls[i].value,
-                                   V4L2_EVENT_CTRL_CH_VALUE);
+                                   changes);
        }
 }