On Tue, May 16, 2017 at 09:29:42AM +0100, Matthew Auld wrote: > When SW enables the use of 2M/1G pages, it must disable the GTT cache. > > Signed-off-by: Matthew Auld <[email protected]> > Cc: Joonas Lahtinen <[email protected]> > --- > drivers/gpu/drm/i915/intel_pm.c | 12 ++++++------ > 1 file changed, 6 insertions(+), 6 deletions(-) > > diff --git a/drivers/gpu/drm/i915/intel_pm.c b/drivers/gpu/drm/i915/intel_pm.c > index ef0e9f8d4dbd..b39b8d394179 100644 > --- a/drivers/gpu/drm/i915/intel_pm.c > +++ b/drivers/gpu/drm/i915/intel_pm.c > @@ -8178,10 +8178,10 @@ static void broadwell_init_clock_gating(struct > drm_i915_private *dev_priv) > > /* > * WaGttCachingOffByDefault:bdw > - * GTT cache may not work with big pages, so if those > - * are ever enabled GTT cache may need to be disabled. > + * The GTT cache must be disabled if the system is planning to use > + * 2M/1G pages. > */ > - I915_WRITE(HSW_GTT_CACHE_EN, GTT_CACHE_EN_ALL); > + I915_WRITE(HSW_GTT_CACHE_EN, 0); > > /* WaKVMNotificationOnConfigChange:bdw */ > I915_WRITE(CHICKEN_PAR2_1, I915_READ(CHICKEN_PAR2_1) > @@ -8457,10 +8457,10 @@ static void cherryview_init_clock_gating(struct > drm_i915_private *dev_priv) > gen8_set_l3sqc_credits(dev_priv, 38, 2); > > /* > - * GTT cache may not work with big pages, so if those > - * are ever enabled GTT cache may need to be disabled. > + * The GTT cache must be disabled if the system is planning to use > + * 2M/1G pages. > */ > - I915_WRITE(HSW_GTT_CACHE_EN, GTT_CACHE_EN_ALL); > + I915_WRITE(HSW_GTT_CACHE_EN, 0); > }
Should we perhaps have a modparam to make it easier to evaluate whether big pages are actually beneficial or not? If so, it should also affect whether we enable the the GTT cache or not. > > static void g4x_init_clock_gating(struct drm_i915_private *dev_priv) > -- > 2.9.4 > > _______________________________________________ > Intel-gfx mailing list > [email protected] > https://lists.freedesktop.org/mailman/listinfo/intel-gfx -- Ville Syrjälä Intel OTC _______________________________________________ Intel-gfx mailing list [email protected] https://lists.freedesktop.org/mailman/listinfo/intel-gfx
