[Intel-gfx] [PATCH 02/19] drm/i915: Call intel_update_watermarks() in specific place during modeset

[Ville Syrjälä]

On Fri, Aug 30, 2013 at 05:26:29PM -0300, Paulo Zanoni wrote:
> 2013/8/30  <ville.syrjala at linux.intel.com>:
> > From: Ville Syrjälä <ville.syrjala at linux.intel.com>
> >
> > Make the call to intel_update_watermarks() just once or twice during
> > modeset. Ideally it should happen independently when each plane gets
> > enabled/disabled, but for now it seems better to keep it in central
> > place. We can improve things when we get all the planes sorted out
> > in a better way.
> >
> > When enabling set up the watermarks just before the pipe is enabled.
> > And when disabling we need to wait until we've marked the crtc as
> > inactive.
> 
> Why do we need to wait until we've marked the CRTC as inactive?
> (Daniel/Ville should put the answer in the commit message)

Because the watermark compute code looks at intel_crtc->active. If we
compute the watermarks before, the code thinks the pipe is active.

Hmm. BTW now that I look at intel_crtc_active() I start to wonder why it
looks at the clock in the user specified mode. In fact most (maybe all?)
of the pre-hsw watermark code is fscked up and it looks at the wrong
mode. Sigh. Suppose I need to make a quick for all that as well...

-- 
Ville Syrjälä
Intel OTC