From mboxrd@z Thu Jan 1 00:00:00 1970 From: Alex Deucher Subject: Re: Vblank timestamping improvements/fixes for Linux drm. Date: Mon, 28 Oct 2013 11:54:09 -0400 Message-ID: References: <1382776062-3770-1-git-send-email-mario.kleiner.de@gmail.com> Mime-Version: 1.0 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable Return-path: In-Reply-To: <1382776062-3770-1-git-send-email-mario.kleiner.de@gmail.com> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: dri-devel-bounces+sf-dri-devel=m.gmane.org@lists.freedesktop.org Errors-To: dri-devel-bounces+sf-dri-devel=m.gmane.org@lists.freedesktop.org To: Mario Kleiner Cc: Intel Graphics Development , Maling list - DRI developers List-Id: dri-devel@lists.freedesktop.org On Sat, Oct 26, 2013 at 4:27 AM, Mario Kleiner wrote: > Hi all, > > this patch set for the kernel pushes the latency sensitive bits of > vblank scanoutpos timestamping from the drm core into the kms drivers. > > A change in the locking of the intel-kms driver for Linux 3.11 made > the old approach too inaccurate and also incompatible with the > PREEMPT_RT realtime kernel patch set. These patches fix that problem > and restore the old level of precision and reliability. > > The patch set changes the prototype of driver->get_scanout_position() > to require/allow kms drivers to perform the ktime_get() system time > queries which go along with actual scanout position readout in a way > that provides maximum precision and to return those timestamps to > the drm. It also converts the only two kms drivers which use this api > so far (intel-kms and radeon-kms) to the new api and improves precision > and reliability of the intel-kms a lot. > > Patches have been tested on Intel and AMD Radeon hardware and the Intel > bits have received some review and feedback by Ville Syrj=E4l=E4. > > Please review and apply if possible. > Looks good to me. For the series: Reviewed-by: Alex Deucher > Thanks, > -mario >