From: Daniel Vetter <daniel@ffwll.ch>
To: Jani Nikula <jani.nikula@linux.intel.com>
Cc: "Ville Syrjälä" <ville.syrjala@linux.intel.com>,
intel-gfx@lists.freedesktop.org, stable@vger.kernel.org
Subject: Re: [Intel-gfx] [PATCH] drm/i915: Disable FBC on Haswell
Date: Tue, 10 Jun 2014 09:06:43 +0200 [thread overview]
Message-ID: <20140610070643.GF5821@phenom.ffwll.local> (raw)
In-Reply-To: <87k38phphm.fsf@intel.com>
On Mon, Jun 09, 2014 at 10:06:29PM +0300, Jani Nikula wrote:
> On Mon, 09 Jun 2014, Ville Syrjälä <ville.syrjala@linux.intel.com> wrote:
> > On Mon, Jun 09, 2014 at 09:12:18PM +0300, Jani Nikula wrote:
> >> On Fri, 06 Jun 2014, Chris Wilson <chris@chris-wilson.co.uk> 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@jonkri.com>
> >> > Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
> >> > 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/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
s/Haswell/Haswell+/ and it's correct ;-)
-Daniel
--
Daniel Vetter
Software Engineer, Intel Corporation
+41 (0) 79 365 57 48 - http://blog.ffwll.ch
next prev parent reply other threads:[~2014-06-10 7:06 UTC|newest]
Thread overview: 7+ messages / expand[flat|nested] mbox.gz Atom feed top
2014-06-06 9:37 [PATCH] drm/i915: Disable FBC on Haswell Chris Wilson
2014-06-06 16:25 ` [Intel-gfx] " Daniel Vetter
2014-06-09 18:12 ` Jani Nikula
2014-06-09 18:36 ` Ville Syrjälä
2014-06-09 19:06 ` Jani Nikula
2014-06-10 7:06 ` Daniel Vetter [this message]
2014-06-10 16:44 ` [Intel-gfx] " Jani Nikula
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=20140610070643.GF5821@phenom.ffwll.local \
--to=daniel@ffwll.ch \
--cc=intel-gfx@lists.freedesktop.org \
--cc=jani.nikula@linux.intel.com \
--cc=stable@vger.kernel.org \
--cc=ville.syrjala@linux.intel.com \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox