[Intel-gfx] [PATCH 7/7] drm/i915/psr: Implement PSR2 w/a for skl/kbl

[Runyan, Arthur J]

SKL+ really means "Gen9 onwards" in bspec terminology, so it includes BXT, KBL, etc.
I don't remember why this one is not labeled as a workaround in PSR2_CTL.  It is listed in the bspec workaround table.  In general everything is going in the table now, not in the associated registers.  I'll send you the internal link.

-----Original Message-----
From: Daniel Vetter [mailto:daniel.vetter at ffwll.ch] 
Sent: Wednesday, May 18, 2016 11:47 AM
To: Ville Syrjälä; Runyan, Arthur J
Cc: Vetter, Daniel; Intel Graphics Development; Pandiyan, Dhinakaran; Vivi, Rodrigo
Subject: Re: [Intel-gfx] [PATCH 7/7] drm/i915/psr: Implement PSR2 w/a for skl/kbl

On Wed, May 18, 2016 at 8:22 PM, Ville Syrjälä
<ville.syrjala at linux.intel.com> wrote:
> On Wed, May 18, 2016 at 06:47:16PM +0200, Daniel Vetter wrote:
>> Found this while browsing Bspec. Looks like it applies to both skl and
>> kbl.
>
> BXT too perhaps. Actually PSR2_CTL says SKL+, but CHICKEN_MISC_1 seems
> to say SKL only.
>
> w/a db is having issues it seems, so I can't check if there's anything
> relevant there.

Maybe Art can clarify? That entry didn't have the usual wa tags, so
maybe not in the wa db. Art, do we need to set bit3 in 0x42080 for
PSR2/selective update mode only on skl, or also on other platforms?
Bspec seems unclear.
-Daniel

>
>>
>> Cc: Rodrigo Vivi <rodrigo.vivi at intel.com>
>> Cc: Sonika Jindal <sonika.jindal at intel.com>
>> Cc: Durgadoss R <durgadoss.r at intel.com>
>> Cc: "Pandiyan, Dhinakaran" <dhinakaran.pandiyan at intel.com>
>> Signed-off-by: Daniel Vetter <daniel.vetter at intel.com>
>> ---
>>  drivers/gpu/drm/i915/i915_reg.h |  1 +
>>  drivers/gpu/drm/i915/intel_pm.c | 13 +++++++++++--
>>  2 files changed, 12 insertions(+), 2 deletions(-)
>>
>> diff --git a/drivers/gpu/drm/i915/i915_reg.h b/drivers/gpu/drm/i915/i915_reg.h
>> index 0f99e67f2114..c51368744e9e 100644
>> --- a/drivers/gpu/drm/i915/i915_reg.h
>> +++ b/drivers/gpu/drm/i915/i915_reg.h
>> @@ -6043,6 +6043,7 @@ enum skl_disp_power_wells {
>>  #define CHICKEN_PAR1_1               _MMIO(0x42080)
>>  #define  DPA_MASK_VBLANK_SRD (1 << 15)
>>  #define  FORCE_ARB_IDLE_PLANES       (1 << 14)
>> +#define  SKL_EDP_PSR_FIX_RDWRAP      (1 << 3)
>>
>>  #define _CHICKEN_PIPESL_1_A  0x420b0
>>  #define _CHICKEN_PIPESL_1_B  0x420b4
>> diff --git a/drivers/gpu/drm/i915/intel_pm.c b/drivers/gpu/drm/i915/intel_pm.c
>> index e0d5405a8b15..c583d1de4555 100644
>> --- a/drivers/gpu/drm/i915/intel_pm.c
>> +++ b/drivers/gpu/drm/i915/intel_pm.c
>> @@ -6845,6 +6845,15 @@ static void gen8_set_l3sqc_credits(struct drm_i915_private *dev_priv,
>>       I915_WRITE(GEN7_MISCCPCTL, misccpctl);
>>  }
>>
>> +static void skylake_init_clock_gating(struct drm_device *dev)
>> +{
>> +     struct drm_i915_private *dev_priv = dev->dev_private;
>> +
>> +     /* See Bspec note for PSR2_CTL bit 31 */
>> +     I915_WRITE(CHICKEN_PAR1_1,
>> +                I915_READ(CHICKEN_PAR1_1) | SKL_EDP_PSR_FIX_RDWRAP);
>> +}
>> +
>>  static void broadwell_init_clock_gating(struct drm_device *dev)
>>  {
>>       struct drm_i915_private *dev_priv = dev->dev_private;
>> @@ -7307,9 +7316,9 @@ static void nop_init_clock_gating(struct drm_device *dev)
>>  void intel_init_clock_gating_hooks(struct drm_i915_private *dev_priv)
>>  {
>>       if (IS_SKYLAKE(dev_priv))
>> -             dev_priv->display.init_clock_gating = nop_init_clock_gating;
>> +             dev_priv->display.init_clock_gating = skylake_init_clock_gating;
>>       else if (IS_KABYLAKE(dev_priv))
>> -             dev_priv->display.init_clock_gating = nop_init_clock_gating;
>> +             dev_priv->display.init_clock_gating = skylake_init_clock_gating;
>>       else if (IS_BROXTON(dev_priv))
>>               dev_priv->display.init_clock_gating = bxt_init_clock_gating;
>>       else if (IS_BROADWELL(dev_priv))
>> --
>> 2.8.1
>>
>> _______________________________________________
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>> Intel-gfx at lists.freedesktop.org
>> https://lists.freedesktop.org/mailman/listinfo/intel-gfx
>
> --
> Ville Syrjälä
> Intel OTC
> _______________________________________________
> Intel-gfx mailing list
> Intel-gfx at lists.freedesktop.org
> https://lists.freedesktop.org/mailman/listinfo/intel-gfx



-- 
Daniel Vetter
Software Engineer, Intel Corporation
+41 (0) 79 365 57 48 - http://blog.ffwll.ch