diff --git a/drivers/gpu/drm/i915/intel_pm.c b/drivers/gpu/drm/i915/intel_pm.c index cb6b26b9134f..25a5c6787ea8 100644 --- a/drivers/gpu/drm/i915/intel_pm.c +++ b/drivers/gpu/drm/i915/intel_pm.c @@ -877,6 +877,17 @@ static void vlv_write_wm_values(struct intel_crtc *crtc, (wm->ddl[pipe].plane[PLANE_SPRITE0] << DDL_SPRITE_SHIFT(0)) | (wm->ddl[pipe].plane[PLANE_PRIMARY] << DDL_PLANE_SHIFT)); + /* + * Zero the (unused) WM1 watermarks, and also clear all the + * high order bits so that there are no out of bounds values + * present in the registers during the reprogramming. + */ + I915_WRITE(DSPHOWM, 0); + I915_WRITE(DSPHOWM1, 0); + I915_WRITE(DSPFW4, 0); + I915_WRITE(DSPFW5, 0); + I915_WRITE(DSPFW6, 0); + I915_WRITE(DSPFW1, FW_WM(wm->sr.plane, SR) | FW_WM(wm->pipe[PIPE_B].plane[PLANE_CURSOR], CURSORB) | @@ -924,12 +935,6 @@ static void vlv_write_wm_values(struct intel_crtc *crtc, FW_WM(wm->pipe[PIPE_A].plane[PLANE_PRIMARY] >> 8, PLANEA_HI)); } - /* zero (unused) WM1 watermarks */ - I915_WRITE(DSPFW4, 0); - I915_WRITE(DSPFW5, 0); - I915_WRITE(DSPFW6, 0); - I915_WRITE(DSPHOWM1, 0); - POSTING_READ(DSPFW1); }