[Intel-gfx] [PATCH v2 3/9] drm/i915: Remove intel_crtc->atomic.disable_ips.

[Maarten Lankhorst]

Op 13-01-16 om 14:02 schreef Ville Syrjälä:
> On Mon, Jan 11, 2016 at 01:27:43PM +0100, Maarten Lankhorst wrote:
>> This is a revert of commit 066cf55b9ce3 "drm/i915: Fix IPS related flicker".
>> intel_pre_disable_primary already handles this, and now everything
>> goes through the atomic path there's no need to try to disable ips twice.
> If it's a revert why wasn't it done with 'git revert'?
A straight revert would fail to apply.
> Also I'm not sure it isn't a step backwards. Based on the spec we should
> be able to keep IPS enabled as long as one plane (possibly referring to 
> either primary or sprite) is enabled on the pipe. So in theory we should
> keep the IPS handling out of the primary plane code, and instead we
> should compute the IPS state based on the set of active planes on the
> pipe.
You're probably right. But pre_disable_primary has the following warning:
     * FIXME IPS should be fine as long as one plane is
     * enabled, but in practice it seems to have problems
     * when going from primary only to sprite only and vice
     * versa.

Hence I'm not doing anything to support that. Even if I did it should be a separate commit.