From mboxrd@z Thu Jan 1 00:00:00 1970 From: Ville =?iso-8859-1?Q?Syrj=E4l=E4?= Subject: Re: [PATCH] drm/i915: Disable FBC on Haswell Date: Mon, 9 Jun 2014 21:36:30 +0300 Message-ID: <20140609183630.GV27580@intel.com> References: <1402047431-32737-1-git-send-email-chris@chris-wilson.co.uk> <87mwdmgdfh.fsf@intel.com> Mime-Version: 1.0 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable Return-path: Received: from mga14.intel.com (mga14.intel.com [192.55.52.115]) by gabe.freedesktop.org (Postfix) with ESMTP id 60EB86E196 for ; Mon, 9 Jun 2014 11:36:34 -0700 (PDT) Content-Disposition: inline In-Reply-To: <87mwdmgdfh.fsf@intel.com> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: intel-gfx-bounces@lists.freedesktop.org Sender: "Intel-gfx" To: Jani Nikula Cc: intel-gfx@lists.freedesktop.org, stable@vger.kernel.org List-Id: intel-gfx@lists.freedesktop.org On Mon, Jun 09, 2014 at 09:12:18PM +0300, Jani Nikula wrote: > On Fri, 06 Jun 2014, Chris Wilson 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=3D79716 > > Reported-and-tested-by: Jon Kristensen > > Signed-off-by: Chris Wilson > > Cc: stable@vger.kernel.org > > --- > > 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/int= el_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 =3D intel_fb->obj; > > adjusted_mode =3D &intel_crtc->config.adjusted_mode; > > = > > - if (i915.enable_fbc < 0 && > > - INTEL_INFO(dev)->gen <=3D 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 <=3D 7 part intact? The current FBC code is universally broken. -- = Ville Syrj=E4l=E4 Intel OTC