drm/i915: Disable LP1+ watermarks safely in init
authorVille Syrjälä <ville.syrjala@linux.intel.com>
Thu, 5 Dec 2013 13:51:37 +0000 (15:51 +0200)
committerDaniel Vetter <daniel.vetter@ffwll.ch>
Tue, 17 Dec 2013 12:17:56 +0000 (13:17 +0100)
commit017636cc09e2c58bc493cc1fe74d858f50d173af
treea22697805e4aa021c311bed1d8db250c8b8f8341
parentce0e0713a6b21ec611d4a2eb5c60d18dbb4bf479
drm/i915: Disable LP1+ watermarks safely in init

ILK doesn't like if we just write the LP1+ watermarks registers with 0.
We need to just disable the watermarks by clearing the enable bit. Use
that method also when disabling LP1+ watermarks in init_clock_gating.

It looks like disabling the sprite LP1 watermarks can cause underruns
even if we just toggle the WM1S_LP_EN bit. So treat that bit like the
actual watermark numbers and avoid setting it to 0 immediately.

Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Reviewed-by: Imre Deak <imre.deak@intel.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
drivers/gpu/drm/i915/intel_pm.c