Hi Kamil, On Mon, Dec 17, 2012 at 12:48:25PM +0100, Kamil Debski wrote: > > From: 'Sakari Ailus' [mailto:sakari.ailus@xxxxxx] > > Sent: Monday, December 17, 2012 12:35 PM > > Subject: Re: [PATCH 4/4] v4l: Tell user space we're using monotonic > > timestamps > > > > Hi Kamil, > > > > On Mon, Dec 17, 2012 at 12:19:51PM +0100, Kamil Debski wrote: > > ... > > > > > @@ -367,7 +368,8 @@ static void __fill_v4l2_buffer(struct > > > > > vb2_buffer > > > > *vb, struct v4l2_buffer *b) > > > > > /* > > > > > * Clear any buffer state related flags. > > > > > */ > > > > > - b->flags &= ~V4L2_BUFFER_STATE_FLAGS; > > > > > + b->flags &= ~V4L2_BUFFER_MASK_FLAGS; > > > > > + b->flags |= V4L2_BUF_FLAG_TIMESTAMP_MONOTONIC; > > > > > > As far as I know, after __fill_v4l2_buffer is run driver has no means > > > to change flags. Right? > > > > Correct. Querybuf, for example, is implemented in vb2 and no driver > > involvement is required. And we sure don't want to add it. ;) > > I did not suggest that it should be added. Good. :-) > > > > > So how should a driver, which is not using the MONOTONIC timestamps > > > inform the user space about it? > > > > We currently support only monotonic timestamps. Support for different > > kind of timestamps should be added to videobuf2 when they are needed. > > The drivers would then be using a videobuf2 equivalent of > > v4l2_get_timestamp(). > > Just as I though. > Mind you - v4l2_get_timestamp() does not apply if the timestamp are simply > copied. > This is the case of some of the mem2mem devices, remember? Yeah. Makes sense. I guess memory-to-memory devices (apart from possibly those dealing with compressed data which contains the timestamps) should just copy the timestamps from output to capture buffers. -- Cheers, Sakari Ailus e-mail: sakari.ailus@xxxxxx XMPP: sailus@xxxxxxxxxxxxxx -- 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
