Re: [PATCH] drm/i915: FBC flush nuke for BDW

[Daniel Vetter <daniel@ffwll.ch>]

On Fri, Sep 05, 2014 at 12:35:18PM -0700, Rodrigo Vivi wrote:
> On Fri, Sep 5, 2014 at 11:28 AM, Paulo Zanoni <przanoni@gmail.com> wrote:
> > - The screen is disabled
> 
> - We're runtime suspended
> >
> 
> These are another error. Not caused by this patch.
> Why frontbuffer_flush is being called with screen disabled or on runtime
> suspend?

Because the frontbuffer tracking only tells you when a frontbuffer gets
updated. It's the job of the consumers to properly filter these events so
that they only act upon those which are relevant. psr does that, fbc (as
is) doesn't.

And if you have that filtering, adding more filtering as a safeguard
really isn't all that useful.

> > - We're touching cursors when we decide to flush FBC.
> >
> 
> This is not actually a flush. But cleaning the cache to allow compression
> restart.
> I believe we could have some variable to indicate when we touched ring
> flush than on next frontbuffer we do the mmio cache clean.

If you filter frontbuffers properly you can ignore all the cursor/sprite
events completely.
-Daniel
-- 
Daniel Vetter
Software Engineer, Intel Corporation
+41 (0) 79 365 57 48 - http://blog.ffwll.ch