[Intel-gfx] [PATCH v2 02/20] drm: Don't update plane properties for atomic planes if it stays the same

[Maarten Lankhorst]

Op 07-07-15 om 14:10 schreef Daniel Vetter:
> On Tue, Jul 07, 2015 at 12:20:10PM +0200, Maarten Lankhorst wrote:
>> Op 07-07-15 om 11:18 schreef Daniel Vetter:
>>> On Tue, Jul 07, 2015 at 09:08:13AM +0200, Maarten Lankhorst wrote:
>>>> This allows the first atomic call during hw init to be a real modeset,
>>>> which is useful for forcing a recalculation.
>>> fbcon is optional, you can't rely on anything being done in any specific
>>> way. What exactly do you need this for, what's the implications?
>> In the hw readout I noticed some warnings when I wasn't setting any mode property in the readout.
>> I want the first function to be the modeset, so we have a sane base to commit changes on.
>> Ideally this whole function would have a atomic counterpart which does it in one go. :)
> Yeah. Otoh as soon as we have atomic modeset working we can replace all
> the legacy entry points with atomic helpers, and then even plane_disable
> will be a full atomic modeset.
>
> What did fall apart with just touching properties/planes now?
Setting rotation on the primary plane caused it to be disabled because
the src and dst rectangle are not set up yet until the modeset. So the
check function saw that the plane should be invisible and performs the
update.

It's also an extra vblank wait when the primary plane is visible.