Re: Vblank timestamping improvements/fixes for Linux drm.

["Ville Syrjälä" <ville.syrjala@linux.intel.com>]

On Sat, Oct 26, 2013 at 10:27:38AM +0200, 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 Syrjälä.
> 
> Please review and apply if possible.

I only have a minor nit about the formatting of multiline comments.

They should look like:
/*
 * foo
 * bar
 */

instead of:
/* foo
 * bar
 */

But other than that I didn't spot any issues, so for the series:

Reviewed-by: Ville Syrjälä <ville.syrjala@linux.intel.com>

-- 
Ville Syrjälä
Intel OTC