[Intel-gfx] [PATCH 1/2] drm/i915: Start WM computation from scratch on ILK-BDW

[ville.syrjala at linux.intel.com]

From: Ville Syrjälä <ville.syrjala at linux.intel.com>

ilk_compute_pipe_wm() assumes as zeroed pipe_wm structure when it
starts. We used to pass such a zeroed struct in, but this got broken
when the pipe_wm structure got embedded in the crtc state.

To fix it without too much fuzz, we need to resort to a memset().

Fixes: 4e0963c7663b ("drm/i915: Calculate pipe watermarks into CRTC state (v3)")
Cc: Matt Roper <matthew.d.roper at intel.com>
Signed-off-by: Ville Syrjälä <ville.syrjala at linux.intel.com>
---
 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 9df9e9a22f3c..e9f4e6e7b736 100644
--- a/drivers/gpu/drm/i915/intel_pm.c
+++ b/drivers/gpu/drm/i915/intel_pm.c
@@ -2317,6 +2317,7 @@ static int ilk_compute_pipe_wm(struct intel_crtc *intel_crtc,
 		return PTR_ERR(cstate);
 
 	pipe_wm = &cstate->wm.optimal.ilk;
+	memset(pipe_wm, 0, sizeof(*pipe_wm));
 
 	for_each_intel_plane_on_crtc(dev, intel_crtc, intel_plane) {
 		ps = drm_atomic_get_plane_state(state,
-- 
2.4.10