[Intel-gfx] [(resend) PATCH 1/2] drm/i915: Calculate vlv/chv intermediate watermarks correctly, v3.

[Maarten Lankhorst]

Op 17-11-17 om 14:31 schreef Ville Syrjälä:
> On Wed, Nov 15, 2017 at 05:31:56PM +0100, Maarten Lankhorst wrote:
>> The watermarks it should calculate against are the old optimal watermarks.
>> The currently active crtc watermarks are pure fiction, and are invalid in
>> case of a nonblocking modeset, page flip enabling/disabling planes or any
>> other reason.
>>
>> When the crtc is disabled or during a modeset the intermediate watermarks
>> don't need to be programmed separately, and could be directly assigned
>> to the optimal watermarks.
>>
>> CXSR must always be disabled in the intermediate case for modesets, else
>> we get a WARN for vblank wait timeout.
>>
>> Also rename crtc_state to new_crtc_state, to distinguish it from the old state.
>>
>> Changes since v1:
>> - Use intel_atomic_get_old_crtc_state. (ville)
>> Changes since v2:
>> - Always unset cxsr during modeset.
>>
>> Signed-off-by: Maarten Lankhorst <maarten.lankhorst at linux.intel.com>
> I was going to try and figure out how/if these get rid of the unclaimed
> reg warns, but I didn't quite get that far. I did spot a few other
> buglets in the wm code though (I'll send fixes for those at some point).
>
> Anyways, these patches make sense to me, so for the series
> Reviewed-by: Ville Syrjälä <ville.syrjala at linux.intel.com>
Seems Chris Wilson already beat us to it..

https://intel-gfx-ci.01.org/tree/drm-tip/igt@kms_pipe_crc_basic@suspend-read-crc-pipe-b.html
was gone with

commit 1a1f12872edcd5e425b668a35fb23548cfa918ef
Author: Chris Wilson <chris at chris-wilson.co.uk <mailto:chris at chris-wilson.co.uk>>
Date:   Tue Nov 7 14:03:38 2017 +0000

    drm/i915: Prevent unbounded wm results in g4x_compute_wm()

But I think this patch also fixes it in a slightly different way, never using garbage for intermediaries. :-)

Thanks for review, pushed.

Cheers,
~Maarten