On Fri, Nov 25, 2016 at 09:23:01AM +0000, Chris Wilson wrote: > On Thu, Nov 24, 2016 at 05:32:59PM +0200, Imre Deak wrote: > > commit 848496e5902833600f7992f4faa82dc1546051ba > > Author: Ville Syrjälä <ville.syrj...@linux.intel.com> > > Date: Wed Jul 13 16:32:03 2016 +0300 > > > > drm/i915: Wait up to 3ms for the pcu to ack the cdclk change request on > > SKL > > > > increased the timeout to match the spec, but we still see a timeout on > > at least one SKL. A CDCLK change request following the failed one will > > succeed nevertheless, so let's try to increase the timeout to 10ms. > > > > Cc: Ville Syrjälä <ville.syrj...@linux.intel.com> > > Reference: https://bugs.freedesktop.org/show_bug.cgi?id=97929 > > Signed-off-by: Imre Deak <imre.d...@intel.com> > > --- > > drivers/gpu/drm/i915/intel_display.c | 2 +- > > 1 file changed, 1 insertion(+), 1 deletion(-) > > > > diff --git a/drivers/gpu/drm/i915/intel_display.c > > b/drivers/gpu/drm/i915/intel_display.c > > index 5d11002..3b711f4 100644 > > --- a/drivers/gpu/drm/i915/intel_display.c > > +++ b/drivers/gpu/drm/i915/intel_display.c > > @@ -6261,7 +6261,7 @@ static bool skl_cdclk_pcu_ready(struct > > drm_i915_private *dev_priv) > > > > static bool skl_cdclk_wait_for_pcu_ready(struct drm_i915_private *dev_priv) > > { > > - return _wait_for(skl_cdclk_pcu_ready(dev_priv), 3000, 10) == 0; > > + return _wait_for(skl_cdclk_pcu_ready(dev_priv), 10000, 10) == 0; > > } > > I can't think of a better approach to kick the pcu. But that is a wakeup > every 10us for 10ms. > > { > int ret; > > ret = wait_for_us(skl_cdclk_pcu_ready(dev_priv), 10); > if (ret) > ret = wait_for(skl_cdclk_pcu_ready(dev_priv), 10); > > return ret; > } > > would spin for the first 10us then do a more gentle probe for the next > 10ms.
Otoh, talking to the pcu also includes such spinners within itself, so probably overkill to spin on top as well. -Chris -- Chris Wilson, Intel Open Source Technology Centre _______________________________________________ Intel-gfx mailing list Intel-gfx@lists.freedesktop.org https://lists.freedesktop.org/mailman/listinfo/intel-gfx
