On Thu, Jul 14, 2016 at 04:39:00PM +0200, Daniel Vetter wrote:
> On Wed, Jul 13, 2016 at 04:32:03PM +0300, ville.syrjala@xxxxxxxxxxxxxxx wrote:
> > From: Ville Syrjälä <ville.syrjala@xxxxxxxxxxxxxxx>
> >
> > Bspec tells us to keep bashing the PCU for up to 3ms when trying to
> > inform it about an upcoming change in the cdclk frequency. Currently
> > we only keep at it for 15*10usec (+ whatever delays gets added by
> > the sandybridge_pcode_read() itself). Let's change the limit to 3ms.
> >
> > I decided to keep 10 usec delay per iteration for now, even though
> > the spec doesn't really tell us to do that.
> >
> > Cc: David Weinehall <david.weinehall@xxxxxxxxx>
> > Signed-off-by: Ville Syrjälä <ville.syrjala@xxxxxxxxxxxxxxx>
>
> Needs
>
> Cc: stable@xxxxxxxxxxxxxxx
>
> and probably also a Fixes: line?
Fixes: 5d96d8afcfbb ("drm/i915/skl: Deinit/init the display at suspend/resume")
and pushed to dinq. Thanks for the review/testing.
> -Daniel
>
> > ---
> > drivers/gpu/drm/i915/intel_display.c | 10 +---------
> > 1 file changed, 1 insertion(+), 9 deletions(-)
> >
> > diff --git a/drivers/gpu/drm/i915/intel_display.c b/drivers/gpu/drm/i915/intel_display.c
> > index be3b2cab2640..90f26f0e2571 100644
> > --- a/drivers/gpu/drm/i915/intel_display.c
> > +++ b/drivers/gpu/drm/i915/intel_display.c
> > @@ -5691,15 +5691,7 @@ 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)
> > {
> > - unsigned int i;
> > -
> > - for (i = 0; i < 15; i++) {
> > - if (skl_cdclk_pcu_ready(dev_priv))
> > - return true;
> > - udelay(10);
> > - }
> > -
> > - return false;
> > + return _wait_for(skl_cdclk_pcu_ready(dev_priv), 3000, 10) == 0;
> > }
> >
> > static void skl_set_cdclk(struct drm_i915_private *dev_priv, int cdclk, int vco)
> > --
> > 2.7.4
> >
> > _______________________________________________
> > Intel-gfx mailing list
> > Intel-gfx@xxxxxxxxxxxxxxxxxxxxx
> > https://lists.freedesktop.org/mailman/listinfo/intel-gfx
>
> --
> Daniel Vetter
> Software Engineer, Intel Corporation
> http://blog.ffwll.ch
--
Ville Syrjälä
Intel OTC
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