[Intel-gfx] [PATCH] drm/i915: Don't forget to reset blocks when testing lower wm levels

[Matt Roper]

On Wed, Dec 12, 2018 at 09:23:38PM +0200, Ville Syrjälä wrote:
> On Wed, Dec 12, 2018 at 11:17:20AM -0800, Matt Roper wrote:
> > During DDB allocation, we try to distribute enough blocks for each plane
> > to hit the highest watermark level; if that fails, we retry each lower
> > level (which should require fewer blocks) until we find one that's
> > possible (or until the whole commit is rejected as impossible).  We need
> > to reset our running block count when trying each lower level, otherwise
> > all lower levels will fail as well.
> > 
> > Cc: Ville Syrjälä <ville.syrjala at linux.intel.com>
> > Fixes: d8e8749802 ("drm/i915: Switch to level-based DDB allocation algorithm (v5)")
> > Signed-off-by: Matt Roper <matthew.d.roper at intel.com>
> 
> Whoops.
> 
> Reviewed-by: Ville Syrjälä <ville.syrjala at linux.intel.com>

Pushed to dinq.  Thanks for the quick review!


Matt

> 
> > ---
> > After waiting for CI results to come out, I accidentally pushed v5 of
> > the new DDB algorithm rather than the expected v6.  This fixup patch is
> > the only difference between those two versions.
> > 
> >  drivers/gpu/drm/i915/intel_pm.c | 1 +
> >  1 file changed, 1 insertion(+)
> > 
> > diff --git a/drivers/gpu/drm/i915/intel_pm.c b/drivers/gpu/drm/i915/intel_pm.c
> > index 6d074f2e69d3..a6c7c11d2c0e 100644
> > --- a/drivers/gpu/drm/i915/intel_pm.c
> > +++ b/drivers/gpu/drm/i915/intel_pm.c
> > @@ -4365,6 +4365,7 @@ skl_allocate_pipe_ddb(struct intel_crtc_state *cstate,
> >  	 * requirement of active planes.
> >  	 */
> >  	for (level = ilk_wm_max_level(dev_priv); level >= 0; level--) {
> > +		blocks = 0;
> >  		for_each_plane_id_on_crtc(intel_crtc, plane_id) {
> >  			if (plane_id == PLANE_CURSOR)
> >  				continue;
> > -- 
> > 2.14.4
> 
> -- 
> Ville Syrjälä
> Intel

-- 
Matt Roper
Graphics Software Engineer
IoTG Platform Enabling & Development
Intel Corporation
(916) 356-2795