Hans Verkuil wrote: > On Monday 22 February 2010 23:47:49 Sakari Ailus wrote: >>>> +Drivers do not initialise events directly. The events are initialised >>>> +through v4l2_fh_init() if video_device->ioctl_ops->vidioc_subscribe_event is >>>> +non-NULL. This *MUST* be performed in the driver's >>>> +v4l2_file_operations->open() handler. >>>> + >>>> +Events are delivered to user space through the poll system call. The driver >>>> +can use v4l2_fh->events->wait wait_queue_head_t as the argument for >>>> +poll_wait(). >>>> + >>>> +There are standard and private events. New standard events must use the >>>> +smallest available event type. The drivers must allocate their events >>>> +starting from base (V4L2_EVENT_PRIVATE_START + n * 1024) while individual >>>> +events start from base + 1. >>> >>> What do you mean with 'while individual events start from base + 1'? I still >>> don't understand that phrase. >> >> Will be "There are standard and private events. New standard events must >> use the smallest available event type. The drivers must allocate their >> events starting from base (V4L2_EVENT_PRIVATE_START + n * 1024) + 1." in >> the next one. > > Ah, OK. But why '+ 1'? I don't really see a reason for that to be honest. > Am I missing something? Many V4L2 control classes do that. No other reason really. :-) Can be removed on my behalf. -- Sakari Ailus sakari.ailus@xxxxxxxxxxxxxxxxxxxxxxxxxx -- To unsubscribe from this list: send the line "unsubscribe linux-media" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
