On Mon, 09 Jun 2014, Ville Syrjälä <ville.syrjala@xxxxxxxxxxxxxxx> wrote: > On Mon, Jun 09, 2014 at 09:12:18PM +0300, Jani Nikula wrote: >> On Fri, 06 Jun 2014, Chris Wilson <chris@xxxxxxxxxxxxxxxxxx> wrote: >> > It causes black screen on bootup and is approximately 100x slower than >> > running with FBC disabled, so the GPU runs at a high frequency for much >> > longer - completely contrary to the power saving claims. It also still >> > has mutex deadlocks in multi-head scenarios, which can lead to a >> > system/X lockup. These bugs were known before FBC was enabled by default >> > on Haswell and still have not been fixed. >> > >> > Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=79716 >> > Reported-and-tested-by: Jon Kristensen <info@xxxxxxxxxx> >> > Signed-off-by: Chris Wilson <chris@xxxxxxxxxxxxxxxxxx> >> > Cc: stable@xxxxxxxxxxxxxxx >> > --- >> > drivers/gpu/drm/i915/intel_pm.c | 3 +-- >> > 1 file changed, 1 insertion(+), 2 deletions(-) >> > >> > diff --git a/drivers/gpu/drm/i915/intel_pm.c b/drivers/gpu/drm/i915/intel_pm.c >> > index e403010540a5..0b8a6010427e 100644 >> > --- a/drivers/gpu/drm/i915/intel_pm.c >> > +++ b/drivers/gpu/drm/i915/intel_pm.c >> > @@ -511,8 +511,7 @@ void intel_update_fbc(struct drm_device *dev) >> > obj = intel_fb->obj; >> > adjusted_mode = &intel_crtc->config.adjusted_mode; >> > >> > - if (i915.enable_fbc < 0 && >> > - INTEL_INFO(dev)->gen <= 7 && !IS_HASWELL(dev)) { >> > + if (i915.enable_fbc < 0) { >> >> Not only does this disable FBC by default on Haswell but also on all >> current and future platforms, including Broadwell. Shouldn't you leave >> the INTEL_INFO(dev)->gen <= 7 part intact? > > The current FBC code is universally broken. Well, then the commit message should reflect that! :p BR, Jani. > > -- > Ville Syrjälä > Intel OTC -- Jani Nikula, Intel Open Source Technology Center -- To unsubscribe from this list: send the line "unsubscribe stable" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html