[Intel-gfx] [PATCH] drm/i915: Program chicken bit during DP MST sequence on TGL+

[Souza, Jose]

On Fri, 2021-07-23 at 10:06 -0700, Matt Roper wrote:
> A new step has been added to the DP modeset sequences for all platforms
> with display version 12 and beyond:  if enabling DP MST with FEC, we
> need to set a chicken bit before enabling the transcoder.  The chicken
> bit should be disabled again before disabling the transcoder (which we
> can do unconditionally since it shouldn't be set anyway in non-MST
> cases).

Reviewed-by: José Roberto de Souza <jose.souza at intel.com>

> 
> Bspec: 49190, 54128, 55424
> Signed-off-by: Matt Roper <matthew.d.roper at intel.com>
> ---
>  drivers/gpu/drm/i915/display/intel_display.c |  4 ++++
>  drivers/gpu/drm/i915/display/intel_dp_mst.c  | 14 +++++++-------
>  drivers/gpu/drm/i915/i915_reg.h              | 19 ++++++++++---------
>  3 files changed, 21 insertions(+), 16 deletions(-)
> 
> diff --git a/drivers/gpu/drm/i915/display/intel_display.c b/drivers/gpu/drm/i915/display/intel_display.c
> index 2b082e1827a8..902826202622 100644
> --- a/drivers/gpu/drm/i915/display/intel_display.c
> +++ b/drivers/gpu/drm/i915/display/intel_display.c
> @@ -1035,6 +1035,10 @@ void intel_disable_pipe(const struct intel_crtc_state *old_crtc_state)
>  	if (!IS_I830(dev_priv))
>  		val &= ~PIPECONF_ENABLE;
>  
> +	if (DISPLAY_VER(dev_priv) >= 12)
> +		intel_de_rmw(dev_priv, CHICKEN_TRANS(cpu_transcoder),
> +			     FECSTALL_DIS_DPTSTREAM_DPTTG, 0);
> +
>  	intel_de_write(dev_priv, reg, val);
>  	if ((val & PIPECONF_ENABLE) == 0)
>  		intel_wait_for_pipe_off(old_crtc_state);
> diff --git a/drivers/gpu/drm/i915/display/intel_dp_mst.c b/drivers/gpu/drm/i915/display/intel_dp_mst.c
> index 3661cd19ce48..e2eb46337369 100644
> --- a/drivers/gpu/drm/i915/display/intel_dp_mst.c
> +++ b/drivers/gpu/drm/i915/display/intel_dp_mst.c
> @@ -542,7 +542,7 @@ static void intel_mst_enable_dp(struct intel_atomic_state *state,
>  	struct intel_digital_port *dig_port = intel_mst->primary;
>  	struct intel_dp *intel_dp = &dig_port->dp;
>  	struct drm_i915_private *dev_priv = to_i915(encoder->base.dev);
> -	u32 val;
> +	enum transcoder trans = pipe_config->cpu_transcoder;
>  
>  	drm_WARN_ON(&dev_priv->drm, pipe_config->has_pch_encoder);
>  
> @@ -550,12 +550,8 @@ static void intel_mst_enable_dp(struct intel_atomic_state *state,
>  
>  	intel_ddi_enable_transcoder_func(encoder, pipe_config);
>  
> -	val = intel_de_read(dev_priv,
> -			    TRANS_DDI_FUNC_CTL(pipe_config->cpu_transcoder));
> -	val |= TRANS_DDI_DP_VC_PAYLOAD_ALLOC;
> -	intel_de_write(dev_priv,
> -		       TRANS_DDI_FUNC_CTL(pipe_config->cpu_transcoder),
> -		       val);
> +	intel_de_rmw(dev_priv, TRANS_DDI_FUNC_CTL(trans), 0,
> +		     TRANS_DDI_DP_VC_PAYLOAD_ALLOC);
>  
>  	drm_dbg_kms(&dev_priv->drm, "active links %d\n",
>  		    intel_dp->active_mst_links);
> @@ -564,6 +560,10 @@ static void intel_mst_enable_dp(struct intel_atomic_state *state,
>  
>  	drm_dp_update_payload_part2(&intel_dp->mst_mgr);
>  
> +	if (DISPLAY_VER(dev_priv) >= 12 && pipe_config->fec_enable)
> +		intel_de_rmw(dev_priv, CHICKEN_TRANS(trans), 0,
> +			     FECSTALL_DIS_DPTSTREAM_DPTTG);
> +
>  	intel_enable_pipe(pipe_config);
>  
>  	intel_crtc_vblank_on(pipe_config);
> diff --git a/drivers/gpu/drm/i915/i915_reg.h b/drivers/gpu/drm/i915/i915_reg.h
> index 8e1392028184..9f1f5e1228f8 100644
> --- a/drivers/gpu/drm/i915/i915_reg.h
> +++ b/drivers/gpu/drm/i915/i915_reg.h
> @@ -8173,15 +8173,16 @@ enum {
>  					    [TRANSCODER_B] = _CHICKEN_TRANS_B, \
>  					    [TRANSCODER_C] = _CHICKEN_TRANS_C, \
>  					    [TRANSCODER_D] = _CHICKEN_TRANS_D))
> -#define  HSW_FRAME_START_DELAY_MASK	(3 << 27)
> -#define  HSW_FRAME_START_DELAY(x)	((x) << 27) /* 0-3 */
> -#define  VSC_DATA_SEL_SOFTWARE_CONTROL	(1 << 25) /* GLK and CNL+ */
> -#define  DDI_TRAINING_OVERRIDE_ENABLE	(1 << 19)
> -#define  DDI_TRAINING_OVERRIDE_VALUE	(1 << 18)
> -#define  DDIE_TRAINING_OVERRIDE_ENABLE	(1 << 17) /* CHICKEN_TRANS_A only */
> -#define  DDIE_TRAINING_OVERRIDE_VALUE	(1 << 16) /* CHICKEN_TRANS_A only */
> -#define  PSR2_ADD_VERTICAL_LINE_COUNT   (1 << 15)
> -#define  PSR2_VSC_ENABLE_PROG_HEADER    (1 << 12)
> +#define  HSW_FRAME_START_DELAY_MASK	REG_GENMASK(28, 27)
> +#define  HSW_FRAME_START_DELAY(x)	REG_FIELD_PREP(HSW_FRAME_START_DELAY_MASK, x)
> +#define  VSC_DATA_SEL_SOFTWARE_CONTROL	REG_BIT(25) /* GLK and CNL+ */
> +#define  FECSTALL_DIS_DPTSTREAM_DPTTG	REG_BIT(23)
> +#define  DDI_TRAINING_OVERRIDE_ENABLE	REG_BIT(19)
> +#define  DDI_TRAINING_OVERRIDE_VALUE	REG_BIT(18)
> +#define  DDIE_TRAINING_OVERRIDE_ENABLE	REG_BIT(17) /* CHICKEN_TRANS_A only */
> +#define  DDIE_TRAINING_OVERRIDE_VALUE	REG_BIT(16) /* CHICKEN_TRANS_A only */
> +#define  PSR2_ADD_VERTICAL_LINE_COUNT	REG_BIT(15)
> +#define  PSR2_VSC_ENABLE_PROG_HEADER	REG_BIT(12)
>  
>  #define DISP_ARB_CTL	_MMIO(0x45000)
>  #define  DISP_FBC_MEMORY_WAKE		(1 << 31)