From mboxrd@z Thu Jan 1 00:00:00 1970 From: Daniel Vetter Subject: Re: [Intel-gfx] [PATCH 1/5] drm/i915: preserve SSC if previously set v2 Date: Tue, 10 Jun 2014 16:00:10 +0200 Message-ID: <20140610140010.GO5821@phenom.ffwll.local> References: <1401992671-2548-1-git-send-email-jbarnes@virtuousgeek.org> 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: <1401992671-2548-1-git-send-email-jbarnes@virtuousgeek.org> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: dri-devel-bounces@lists.freedesktop.org Sender: "dri-devel" To: Jesse Barnes Cc: intel-gfx@lists.freedesktop.org, dri-devel@lists.freedesktop.org List-Id: intel-gfx@lists.freedesktop.org On Thu, Jun 05, 2014 at 11:24:27AM -0700, Jesse Barnes wrote: > Some machines may have a broken VBT or no VBT at all, but we still want > to use SSC there. So check for it and keep it enabled if we see it > already on. Based on an earlier fix from Kristian. > = > v2: honor modparam if set too (Daniel) > read out at init time and store for panel_use_ssc() use (Jesse) > = > Reported-by: Kristian H=F8gsberg > Signed-off-by: Jesse Barnes Ugh. This means the BIOS idea of when we need SSC and ours are diverging, which isn't good. And I think we should further lock this down by tracking the "uses SSC refclk" state in the pipe config, just to make sure we don't fumble this. -Daniel > --- > drivers/gpu/drm/i915/i915_drv.h | 2 ++ > drivers/gpu/drm/i915/intel_display.c | 11 ++++++++++- > 2 files changed, 12 insertions(+), 1 deletion(-) > = > diff --git a/drivers/gpu/drm/i915/i915_drv.h b/drivers/gpu/drm/i915/i915_= drv.h > index 8631fb3..f57b752 100644 > --- a/drivers/gpu/drm/i915/i915_drv.h > +++ b/drivers/gpu/drm/i915/i915_drv.h > @@ -1404,6 +1404,8 @@ struct drm_i915_private { > struct intel_opregion opregion; > struct intel_vbt_data vbt; > = > + bool bios_ssc; /* BIOS had SSC enabled at boot? */ > + > /* overlay */ > struct intel_overlay *overlay; > = > diff --git a/drivers/gpu/drm/i915/intel_display.c b/drivers/gpu/drm/i915/= intel_display.c > index b5cbb28..0e8c9bc 100644 > --- a/drivers/gpu/drm/i915/intel_display.c > +++ b/drivers/gpu/drm/i915/intel_display.c > @@ -5355,7 +5355,7 @@ static inline bool intel_panel_use_ssc(struct drm_i= 915_private *dev_priv) > { > if (i915.panel_use_ssc >=3D 0) > return i915.panel_use_ssc !=3D 0; > - return dev_priv->vbt.lvds_use_ssc > + return (dev_priv->vbt.lvds_use_ssc || dev_priv->bios_ssc) > && !(dev_priv->quirks & QUIRK_LVDS_SSC_DISABLE); > } > = > @@ -12478,6 +12478,7 @@ void intel_modeset_setup_hw_state(struct drm_devi= ce *dev, > = > void intel_modeset_gem_init(struct drm_device *dev) > { > + struct drm_i915_private *dev_priv =3D dev->dev_private; > struct drm_crtc *c; > struct intel_framebuffer *fb; > = > @@ -12485,6 +12486,14 @@ void intel_modeset_gem_init(struct drm_device *d= ev) > intel_init_gt_powersave(dev); > mutex_unlock(&dev->struct_mutex); > = > + /* > + * There may be no VBT; and if the BIOS enabled SSC we can > + * just keep using it to avoid unnecessary flicker. > + */ > + if ((HAS_PCH_IBX(dev) || HAS_PCH_CPT(dev)) && > + (I915_READ(PCH_DREF_CONTROL) & DREF_SSC1_ENABLE)) > + dev_priv->bios_ssc =3D true; > + > intel_modeset_init_hw(dev); > = > intel_setup_overlay(dev); > -- = > 1.8.3.2 > = > _______________________________________________ > Intel-gfx mailing list > Intel-gfx@lists.freedesktop.org > http://lists.freedesktop.org/mailman/listinfo/intel-gfx -- = Daniel Vetter Software Engineer, Intel Corporation +41 (0) 79 365 57 48 - http://blog.ffwll.ch