From 6e6d76cdc541e28bf4f609141d76c488c6c0d263 Mon Sep 17 00:00:00 2001 From: Hans Verkuil Date: Mon, 7 May 2012 16:53:20 -0300 Subject: [PATCH] [media] v4l2-event: fix regression with initial event handling If the V4L2_EVENT_SUB_FL_SEND_INITIAL was set, then the application expects to receive an initial event of the initial value of the control. However, commit c53c2549333b340e2662dc64ec81323476b69a97 that added the new v4l2_subscribed_event_ops introduced a regression: while the code still queued that initial event the __v4l2_event_queue_fh() function was modified to ignore such requests if sev->elems was 0 (meaning that the event subscription wasn't finished yet). And sev->elems was only set to a non-zero value after the add operation returned. This patch fixes this by passing the elems value to the add function. Then the add function can set it before queuing the initial event. Signed-off-by: Hans Verkuil Acked-by: Hans de Goede Signed-off-by: Mauro Carvalho Chehab --- drivers/media/video/uvc/uvc_ctrl.c | 5 ++++- drivers/media/video/v4l2-ctrls.c | 5 ++++- drivers/media/video/v4l2-event.c | 2 +- include/media/v4l2-event.h | 2 +- 4 files changed, 10 insertions(+), 4 deletions(-) diff --git a/drivers/media/video/uvc/uvc_ctrl.c b/drivers/media/video/uvc/uvc_ctrl.c index 28363b72ff8a..f3bd66c500b6 100644 --- a/drivers/media/video/uvc/uvc_ctrl.c +++ b/drivers/media/video/uvc/uvc_ctrl.c @@ -1250,7 +1250,7 @@ static void uvc_ctrl_send_events(struct uvc_fh *handle, } } -static int uvc_ctrl_add_event(struct v4l2_subscribed_event *sev) +static int uvc_ctrl_add_event(struct v4l2_subscribed_event *sev, unsigned elems) { struct uvc_fh *handle = container_of(sev->fh, struct uvc_fh, vfh); struct uvc_control_mapping *mapping; @@ -1278,6 +1278,9 @@ static int uvc_ctrl_add_event(struct v4l2_subscribed_event *sev) uvc_ctrl_fill_event(handle->chain, &ev, ctrl, mapping, val, changes); + /* Mark the queue as active, allowing this initial + event to be accepted. */ + sev->elems = elems; v4l2_event_queue_fh(sev->fh, &ev); } diff --git a/drivers/media/video/v4l2-ctrls.c b/drivers/media/video/v4l2-ctrls.c index a5fbace4c059..9abd9abd4502 100644 --- a/drivers/media/video/v4l2-ctrls.c +++ b/drivers/media/video/v4l2-ctrls.c @@ -2559,7 +2559,7 @@ int v4l2_ctrl_s_ctrl(struct v4l2_ctrl *ctrl, s32 val) } EXPORT_SYMBOL(v4l2_ctrl_s_ctrl); -static int v4l2_ctrl_add_event(struct v4l2_subscribed_event *sev) +static int v4l2_ctrl_add_event(struct v4l2_subscribed_event *sev, unsigned elems) { struct v4l2_ctrl *ctrl = v4l2_ctrl_find(sev->fh->ctrl_handler, sev->id); @@ -2576,6 +2576,9 @@ static int v4l2_ctrl_add_event(struct v4l2_subscribed_event *sev) if (!(ctrl->flags & V4L2_CTRL_FLAG_WRITE_ONLY)) changes |= V4L2_EVENT_CTRL_CH_VALUE; fill_event(&ev, ctrl, changes); + /* Mark the queue as active, allowing this initial + event to be accepted. */ + sev->elems = elems; v4l2_event_queue_fh(sev->fh, &ev); } v4l2_ctrl_unlock(ctrl); diff --git a/drivers/media/video/v4l2-event.c b/drivers/media/video/v4l2-event.c index 60b4e2e9c874..ef2a33c94045 100644 --- a/drivers/media/video/v4l2-event.c +++ b/drivers/media/video/v4l2-event.c @@ -239,7 +239,7 @@ int v4l2_event_subscribe(struct v4l2_fh *fh, } if (sev->ops && sev->ops->add) { - int ret = sev->ops->add(sev); + int ret = sev->ops->add(sev, elems); if (ret) { sev->ops = NULL; v4l2_event_unsubscribe(fh, sub); diff --git a/include/media/v4l2-event.h b/include/media/v4l2-event.h index 88fa9a1e0df3..2885a810a128 100644 --- a/include/media/v4l2-event.h +++ b/include/media/v4l2-event.h @@ -85,7 +85,7 @@ struct v4l2_kevent { * @merge: Optional callback that can merge event 'old' into event 'new'. */ struct v4l2_subscribed_event_ops { - int (*add)(struct v4l2_subscribed_event *sev); + int (*add)(struct v4l2_subscribed_event *sev, unsigned elems); void (*del)(struct v4l2_subscribed_event *sev); void (*replace)(struct v4l2_event *old, const struct v4l2_event *new); void (*merge)(const struct v4l2_event *old, struct v4l2_event *new); -- 2.30.2