diff --git a/drivers/gpu/drm/i915/intel_display.c b/drivers/gpu/drm/i915/intel_display.c index 09659ff6d24d..0a02e044b653 100644 --- a/drivers/gpu/drm/i915/intel_display.c +++ b/drivers/gpu/drm/i915/intel_display.c @@ -3604,6 +3604,30 @@ static void intel_crtc_dpms_overlay(struct intel_crtc *intel_crtc, bool enable) */ } +/** + * i9xx_fixup_plane - ugly workaround for G45 to fire up the hardware + * cursor plane briefly if not already running after enabling the display + * plane. + * This workaround avoids occasional blank screens when self refresh is + * enabled. + */ +static void +g4x_fixup_plane(struct drm_i915_private *dev_priv, enum pipe pipe) +{ + u32 cntl = I915_READ(CURCNTR(pipe)); + + if ((cntl & CURSOR_MODE) == 0) { + u32 fw_bcl_self = I915_READ(FW_BLC_SELF); + + I915_WRITE(FW_BLC_SELF, fw_bcl_self & ~FW_BLC_SELF_EN); + I915_WRITE(CURCNTR(pipe), CURSOR_MODE_64_ARGB_AX); + intel_wait_for_vblank(dev_priv->dev, pipe); + I915_WRITE(CURCNTR(pipe), cntl); + I915_WRITE(CURBASE(pipe), I915_READ(CURBASE(pipe))); + I915_WRITE(FW_BLC_SELF, fw_bcl_self); + } +} + static void i9xx_crtc_enable(struct drm_crtc *crtc) { struct drm_device *dev = crtc->dev; @@ -3629,6 +3653,8 @@ static void i9xx_crtc_enable(struct drm_crtc *crtc) intel_enable_pipe(dev_priv, pipe, false); intel_enable_plane(dev_priv, plane, pipe); + if (IS_G4X(dev)) + g4x_fixup_plane(dev_priv, pipe); intel_crtc_load_lut(crtc); intel_update_fbc(dev);