From: Imre Deak <imre.deak@intel.com>
To: "Michel Dänzer" <michel@daenzer.net>
Cc: Daniel Vetter <daniel.vetter@ffwll.ch>,
intel-gfx@lists.freedesktop.org, dri-devel@lists.freedesktop.org
Subject: Re: [RFC 4/4] drm: add support for raw monotonic vblank timestamps
Date: Fri, 05 Oct 2012 16:59:04 +0300 [thread overview]
Message-ID: <1349445544.17509.13.camel@localhost> (raw)
In-Reply-To: <1349445311.17758.69.camel@thor.local>
On Fri, 2012-10-05 at 15:55 +0200, Michel Dänzer wrote:
> On Fre, 2012-10-05 at 16:37 +0300, Imre Deak wrote:
> > In practice we never want the timestamps for vblank and page flip events
> > to be affected by time adjustments, so in addition to the gettimeofday
> > timestamps we used so far add support for raw monotonic timestamps.
> >
> > For backward compatibility use flags to select between the old and new
> > timestamp format.
> >
> > Note that with this change we will save the timestamp in both formats,
> > for cases where multiple clients are expecting an event notification in
> > different time formats.
>
> I wonder if all this trouble is really necessary. I honestly can't
> imagine any user of this API requiring non-monotonic timestamps and
> breaking with monotonic ones. I think it was simply a mistake that we
> didn't make them monotonic in the first place (or maybe it wasn't even
> possible when this API was first introduced).
Yea, I'd rather simply switch over to monotonic timestamps too. But that
would break apps that already compare against the wall time for whatever
purpose (for example A/V sync).
--Imre
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next prev parent reply other threads:[~2012-10-05 13:59 UTC|newest]
Thread overview: 30+ messages / expand[flat|nested] mbox.gz Atom feed top
2012-10-05 13:36 [RFC 0/4] drm: add raw monotonic timestamp support Imre Deak
2012-10-05 13:36 ` [RFC 1/4] time: export getnstime_raw_and_real for DRM Imre Deak
2012-10-05 16:14 ` Kristian Høgsberg
2012-10-09 10:25 ` Imre Deak
2012-10-05 13:37 ` [RFC 2/4] drm: make memset/calloc for _vblank_time more robust Imre Deak
2012-10-05 13:37 ` [RFC 3/4] drm: use raw time in drm_calc_vbltimestamp_from_scanoutpos Imre Deak
2012-10-05 13:37 ` [RFC 4/4] drm: add support for raw monotonic vblank timestamps Imre Deak
2012-10-05 13:55 ` Michel Dänzer
2012-10-05 13:59 ` Imre Deak [this message]
2012-10-05 14:14 ` Michel Dänzer
2012-10-05 14:21 ` Imre Deak
2012-10-05 22:18 ` Rob Clark
2012-10-05 23:41 ` Imre Deak
2012-10-06 0:09 ` Rob Clark
2012-10-06 0:49 ` Imre Deak
2012-10-07 20:33 ` Daniel Vetter
2012-10-05 23:07 ` [RFC 0/4] drm: add raw monotonic timestamp support Eric Anholt
2012-10-08 11:22 ` Imre Deak
2012-10-11 10:29 ` Laurent Pinchart
2012-10-11 11:21 ` Imre Deak
2012-10-11 10:32 ` Laurent Pinchart
2012-10-11 11:22 ` Imre Deak
2012-10-23 18:53 ` [PATCH 0/2] drm: add " Imre Deak
2012-10-23 18:53 ` [PATCH 1/2] drm: use monotonic time in drm_calc_vbltimestamp_from_scanoutpos Imre Deak
2012-10-24 23:05 ` Mario Kleiner
2012-10-25 10:28 ` Imre Deak
2012-10-25 19:45 ` Mario Kleiner
2012-10-23 18:53 ` [PATCH 2/2] drm: add support for monotonic vblank timestamps Imre Deak
2012-10-24 8:08 ` Michel Dänzer
2012-10-24 11:40 ` Imre Deak
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