diff options
| -rw-r--r-- | drivers/gpu/drm/i915/intel_display.c | 8 |
1 files changed, 8 insertions, 0 deletions
diff --git a/drivers/gpu/drm/i915/intel_display.c b/drivers/gpu/drm/i915/intel_display.c index a6d8698d36a..f5126b81b43 100644 --- a/drivers/gpu/drm/i915/intel_display.c +++ b/drivers/gpu/drm/i915/intel_display.c @@ -3346,6 +3346,14 @@ void hsw_enable_ips(struct intel_crtc *crtc) * for a vblank, so all we need to do here is to enable the IPS bit. */ assert_plane_enabled(dev_priv, crtc->plane); I915_WRITE(IPS_CTL, IPS_ENABLE); + + /* The bit only becomes 1 in the next vblank, so this wait here is + * essentially intel_wait_for_vblank. If we don't have this and don't + * wait for vblanks until the end of crtc_enable, then the HW state + * readout code will complain that the expected IPS_CTL value is not the + * one we read. */ + if (wait_for(I915_READ_NOTRACE(IPS_CTL) & IPS_ENABLE, 50)) + DRM_ERROR("Timed out waiting for IPS enable\n"); } void hsw_disable_ips(struct intel_crtc *crtc) |