From mboxrd@z Thu Jan 1 00:00:00 1970 From: Daniel Vetter Subject: Re: [Intel-gfx] [PATCH] drm/i915: Disable FBC on Haswell Date: Tue, 10 Jun 2014 09:06:43 +0200 Message-ID: <20140610070643.GF5821@phenom.ffwll.local> References: <1402047431-32737-1-git-send-email-chris@chris-wilson.co.uk> <87mwdmgdfh.fsf@intel.com> <20140609183630.GV27580@intel.com> <87k38phphm.fsf@intel.com> Mime-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1 Content-Transfer-Encoding: QUOTED-PRINTABLE Return-path: Content-Disposition: inline In-Reply-To: <87k38phphm.fsf@intel.com> Sender: stable-owner@vger.kernel.org To: Jani Nikula Cc: Ville =?iso-8859-1?Q?Syrj=E4l=E4?= , intel-gfx@lists.freedesktop.org, stable@vger.kernel.org List-Id: intel-gfx@lists.freedesktop.org On Mon, Jun 09, 2014 at 10:06:29PM +0300, Jani Nikula wrote: > On Mon, 09 Jun 2014, Ville Syrj=E4l=E4 wrote: > > 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 slowe= r than > >> > running with FBC disabled, so the GPU runs at a high frequency f= or 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/i= 915/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 =3D intel_fb->obj; > >> > adjusted_mode =3D &intel_crtc->config.adjusted_mode; > >> > =20 > >> > - if (i915.enable_fbc < 0 && > >> > - INTEL_INFO(dev)->gen <=3D 7 && !IS_HASWELL(dev)) { > >> > + if (i915.enable_fbc < 0) { > >>=20 > >> Not only does this disable FBC by default on Haswell but also on a= ll > >> current and future platforms, including Broadwell. Shouldn't you l= eave > >> the INTEL_INFO(dev)->gen <=3D 7 part intact? > > > > The current FBC code is universally broken. >=20 > Well, then the commit message should reflect that! :p s/Haswell/Haswell+/ and it's correct ;-) -Daniel --=20 Daniel Vetter Software Engineer, Intel Corporation +41 (0) 79 365 57 48 - http://blog.ffwll.ch