[Intel-gfx] [PATCH 2/2] drm/i915/display: Implement Wa_16013835468

[Hogander, Jouni]

On Wed, 2022-02-16 at 13:48 +0000, Souza, Jose wrote:
> On Tue, 2022-02-15 at 12:31 +0000, Hogander, Jouni wrote:
> > On Thu, 2022-02-10 at 10:52 -0800, José Roberto de Souza wrote:
> > > PSR2 workaround required when mode has delayed vblank.
> > > 
> > > BSpec: 52890
> > > BSpec: 49421
> > > Cc: Jouni Högander <jouni.hogander at intel.com>
> > > Signed-off-by: José Roberto de Souza <jose.souza at intel.com>
> > > ---
> > >  drivers/gpu/drm/i915/display/intel_psr.c | 40
> > > ++++++++++++++++++++++--
> > >  drivers/gpu/drm/i915/i915_reg.h          | 13 +++++---
> > >  2 files changed, 46 insertions(+), 7 deletions(-)
> > > 
> > > diff --git a/drivers/gpu/drm/i915/display/intel_psr.c
> > > b/drivers/gpu/drm/i915/display/intel_psr.c
> > > index 72bd8d3261e0c..2e0b092f4b6be 100644
> > > --- a/drivers/gpu/drm/i915/display/intel_psr.c
> > > +++ b/drivers/gpu/drm/i915/display/intel_psr.c
> > > @@ -1063,7 +1063,23 @@ static void intel_psr_activate(struct
> > > intel_dp
> > > *intel_dp)
> > >       intel_dp->psr.active = true;
> > >  }
> > > 
> > > -static void intel_psr_enable_source(struct intel_dp *intel_dp)
> > > +static u32 wa_16013835468_bit_get(struct intel_dp *intel_dp)
> > > +{
> > > +     switch (intel_dp->psr.pipe) {
> > > +     case PIPE_A:
> > > +             return LATENCY_REPORTING_REMOVED_PIPE_A;
> > > +     case PIPE_B:
> > > +             return LATENCY_REPORTING_REMOVED_PIPE_B;
> > > +     case PIPE_C:
> > > +             return LATENCY_REPORTING_REMOVED_PIPE_C;
> > > +     default:
> > > +             MISSING_CASE(intel_dp->psr.pipe);
> > > +             return 0;
> > > +     }
> > > +}
> > > +
> > > +static void intel_psr_enable_source(struct intel_dp *intel_dp,
> > > +                                 const struct intel_crtc_state
> > > *crtc_state)
> > >  {
> > >       struct drm_i915_private *dev_priv = dp_to_i915(intel_dp);
> > >       enum transcoder cpu_transcoder = intel_dp->psr.transcoder;
> > > @@ -1133,6 +1149,20 @@ static void intel_psr_enable_source(struct
> > > intel_dp *intel_dp)
> > >               if (IS_ALDERLAKE_P(dev_priv))
> > >                       intel_de_rmw(dev_priv, CLKGATE_DIS_MISC, 0,
> > >                                    CLKGATE_DIS_MISC_DMASC_GATING_
> > > DIS)
> > > ;
> > > +
> > > +             /* Wa_16013835468:tgl[b0+], dg1 */
> > > +             if (IS_TGL_DISPLAY_STEP(dev_priv, STEP_B0,
> > > STEP_FOREVER) ||
> > > +                 IS_DG1(dev_priv)) {
> > > +                     u16 vtotal, vblank;
> > > +
> > > +                     vtotal = crtc_state-
> > > > uapi.adjusted_mode.crtc_vtotal -
> > > +                              crtc_state-
> > > > uapi.adjusted_mode.crtc_vdisplay;
> > > +                     vblank = crtc_state-
> > > > uapi.adjusted_mode.crtc_vblank_end -
> > > +                              crtc_state-
> > > > uapi.adjusted_mode.crtc_vblank_start;
> > > +                     if (vblank > vtotal)
> > 
> > Can you please explain how this calculation indicates we are using
> > "delayed vblank"?
> 
> Check the second box in Bspec 49265

Thank you for pointing this out.

> 
> 
> > Otherwise patch seems to be doing what is written in WA
> > description.
> > 
> > > +                             intel_de_rmw(dev_priv,
> > > GEN8_CHICKEN_DCPR_1, 0,
> > > +                                          wa_16013835468_bit_get
> > > (int
> > > el_dp));
> > > +             }
> > >       }
> > >  }
> > > 
> > > @@ -1198,7 +1228,7 @@ static void intel_psr_enable_locked(struct
> > > intel_dp *intel_dp,
> > >       intel_write_dp_vsc_sdp(encoder, crtc_state, &crtc_state-
> > > > psr_vsc);
> > >       intel_snps_phy_update_psr_power_state(dev_priv, phy, true);
> > >       intel_psr_enable_sink(intel_dp);
> > > -     intel_psr_enable_source(intel_dp);
> > > +     intel_psr_enable_source(intel_dp, crtc_state);
> > >       intel_dp->psr.enabled = true;
> > >       intel_dp->psr.paused = false;
> > > 
> > > @@ -1297,6 +1327,12 @@ static void
> > > intel_psr_disable_locked(struct
> > > intel_dp *intel_dp)
> > >               if (IS_ALDERLAKE_P(dev_priv))
> > >                       intel_de_rmw(dev_priv, CLKGATE_DIS_MISC,
> > >                                    CLKGATE_DIS_MISC_DMASC_GATING_
> > > DIS,
> > > 0);
> > > +
> > > +             /* Wa_16013835468:tgl[b0+], dg1 */
> > > +             if (IS_TGL_DISPLAY_STEP(dev_priv, STEP_B0,
> > > STEP_FOREVER) ||
> > > +                 IS_DG1(dev_priv))
> > > +                     intel_de_rmw(dev_priv, GEN8_CHICKEN_DCPR_1,
> > > +                                  wa_16013835468_bit_get(intel_d
> > > p),
> > > 0);
> > >       }
> > > 
> > >       intel_snps_phy_update_psr_power_state(dev_priv, phy,
> > > false);
> > > diff --git a/drivers/gpu/drm/i915/i915_reg.h
> > > b/drivers/gpu/drm/i915/i915_reg.h
> > > index 87c92314ee269..1cd4056400b63 100644
> > > --- a/drivers/gpu/drm/i915/i915_reg.h
> > > +++ b/drivers/gpu/drm/i915/i915_reg.h
> > > @@ -6040,11 +6040,14 @@
> > >  #define HSW_NDE_RSTWRN_OPT   _MMIO(0x46408)
> > >  #define  RESET_PCH_HANDSHAKE_ENABLE  (1 << 4)
> > > 
> > > -#define GEN8_CHICKEN_DCPR_1          _MMIO(0x46430)
> > > -#define   SKL_SELECT_ALTERNATE_DC_EXIT       REG_BIT(30)
> > > -#define   ICL_DELAY_PMRSP            REG_BIT(22)
> > > -#define   DISABLE_FLR_SRC            REG_BIT(15)
> > > -#define   MASK_WAKEMEM                       REG_BIT(13)
> > > +#define GEN8_CHICKEN_DCPR_1                  _MMIO(0x46430)
> > > +#define   SKL_SELECT_ALTERNATE_DC_EXIT               REG_BIT(30)
> > > +#define   LATENCY_REPORTING_REMOVED_PIPE_C   REG_BIT(25)
> > > +#define   LATENCY_REPORTING_REMOVED_PIPE_B   REG_BIT(24)
> > > +#define   LATENCY_REPORTING_REMOVED_PIPE_A   REG_BIT(23)
> > > +#define   ICL_DELAY_PMRSP                    REG_BIT(22)
> > > +#define   DISABLE_FLR_SRC                    REG_BIT(15)
> > > +#define   MASK_WAKEMEM                               REG_BIT(13)
> > > 
> > >  #define GEN11_CHICKEN_DCPR_2                 _MMIO(0x46434)
> > >  #define   DCPR_MASK_MAXLATENCY_MEMUP_CLR     REG_BIT(27)
> > 
> > BR,
> > 
> > Jouni Högander

BR,

Jouni Högander