Re: [PATCH 15/49] drm/i915/bxt: add GEN8_HDCUNIT_CLOCK_GATE_DISABLE_HDCREQ workaround

Imre Deak
2015-04-08T13:10:05Z

On ke, 2015-04-08 at 14:04 +0100, Nick Hoath wrote:
> On 17/03/2015 09:39, Imre Deak wrote:
> > From: Ben Widawsky <benjamin.widawsky@intel.com>
> >
> > Signed-off-by: Ben Widawsky <ben@bwidawsk.net>
> > Signed-off-by: Imre Deak <imre.deak@intel.com>
> > ---
> > drivers/gpu/drm/i915/i915_reg.h | 1 +
> > drivers/gpu/drm/i915/intel_pm.c | 4 +++-
> > 2 files changed, 4 insertions(+), 1 deletion(-)
> >
> > diff --git a/drivers/gpu/drm/i915/i915_reg.h b/drivers/gpu/drm/i915/i915_reg.h
> > index 3369a11..b7ba061 100644
> > --- a/drivers/gpu/drm/i915/i915_reg.h
> > +++ b/drivers/gpu/drm/i915/i915_reg.h
> > @@ -6104,6 +6104,7 @@ enum skl_disp_power_wells {
> > #define GEN8_UCGCTL6 0x9430
> > #define GEN8_GAPSUNIT_CLOCK_GATE_DISABLE (1<<24)
> > #define GEN8_SDEUNIT_CLOCK_GATE_DISABLE (1<<14)
> > +#define GEN8_HDCUNIT_CLOCK_GATE_DISABLE_HDCREQ (1<<28)
> >
> > #define GEN6_GFXPAUSE 0xA000
> > #define GEN6_RPNSWREQ 0xA008
> > diff --git a/drivers/gpu/drm/i915/intel_pm.c b/drivers/gpu/drm/i915/intel_pm.c
> > index d5dd0b3..52d3c02 100644
> > --- a/drivers/gpu/drm/i915/intel_pm.c
> > +++ b/drivers/gpu/drm/i915/intel_pm.c
> > @@ -103,10 +103,12 @@ static void bxt_init_clock_gating(struct drm_device *dev)
> > /*
> > * FIXME:
> > * GEN8_SDEUNIT_CLOCK_GATE_DISABLE applies on A0 only.
> > + * GEN8_HDCUNIT_CLOCK_GATE_DISABLE_HDCREQ applies on 3x6 GT SKUs only.
> > */
> > /* WaDisableSDEUnitClockGating:bxt */
>
> I can't find where WaDisableSDEUnitClockGating is listed as required for
> BXT?

It's specified in BSpec GEN8_UCGCTL6 (0x9430) as required for BXT A0.

--Imre