Re: [PATCH 09/10] drm/i915/xe3lpd: Add check to see if edp over type c is allowed

[Jani Nikula <jani.nikula@linux.intel.com>]

On Tue, 08 Oct 2024, Matt Atwood <matthew.s.atwood@intel.com> wrote:
> From: Suraj Kandpal <suraj.kandpal@intel.com>
>
> Read PICA register to see if edp over type C is possible and then
> add the appropriate tables for it.

There's clearly more to be done for the feature than this.

>
> Bspec: 68846
> Signed-off-by: Suraj Kandpal <suraj.kandpal@intel.com>
> Signed-off-by: Matt Atwood <matthew.s.atwood@intel.com>
> ---
>  drivers/gpu/drm/i915/display/intel_cx0_phy.c     |  2 ++
>  .../gpu/drm/i915/display/intel_display_types.h   |  1 +
>  drivers/gpu/drm/i915/display/intel_dp.c          | 16 ++++++++++++++++
>  drivers/gpu/drm/i915/i915_reg.h                  |  3 +++
>  4 files changed, 22 insertions(+)
>
> diff --git a/drivers/gpu/drm/i915/display/intel_cx0_phy.c b/drivers/gpu/drm/i915/display/intel_cx0_phy.c
> index 0d6f75ae35f5..1c8c2a2b05e1 100644
> --- a/drivers/gpu/drm/i915/display/intel_cx0_phy.c
> +++ b/drivers/gpu/drm/i915/display/intel_cx0_phy.c
> @@ -2261,6 +2261,8 @@ intel_c20_pll_tables_get(struct intel_crtc_state *crtc_state,
>  		if (intel_crtc_has_type(crtc_state, INTEL_OUTPUT_EDP)) {
>  			if (DISPLAY_VER_FULL(i915) == IP_VER(14, 1))
>  				return xe2hpd_c20_edp_tables;
> +			if (DISPLAY_VER(i915) >= 30 && encoder->typec_supp)
> +				return xe3lpd_c20_dp_edp_tables;
>  		}
>  
>  		if (DISPLAY_VER_FULL(i915) == IP_VER(14, 1))
> diff --git a/drivers/gpu/drm/i915/display/intel_display_types.h b/drivers/gpu/drm/i915/display/intel_display_types.h
> index 2bb1fa64da2f..e9dc7707fbcd 100644
> --- a/drivers/gpu/drm/i915/display/intel_display_types.h
> +++ b/drivers/gpu/drm/i915/display/intel_display_types.h
> @@ -158,6 +158,7 @@ struct intel_encoder {
>  	enum port port;
>  	u16 cloneable;
>  	u8 pipe_mask;
> +	bool typec_supp;

The register is global, why do we store this per encoder?

Side not, please let's not abbreviate stuff like _supp for the sake of
abbreviating stuff.

>  
>  	/* Check and recover a bad link state. */
>  	struct delayed_work link_check_work;
> diff --git a/drivers/gpu/drm/i915/display/intel_dp.c b/drivers/gpu/drm/i915/display/intel_dp.c
> index fbb096be02ad..917a503cc43b 100644
> --- a/drivers/gpu/drm/i915/display/intel_dp.c
> +++ b/drivers/gpu/drm/i915/display/intel_dp.c
> @@ -5570,6 +5570,20 @@ intel_dp_detect_sdp_caps(struct intel_dp *intel_dp)
>  		drm_dp_as_sdp_supported(&intel_dp->aux, intel_dp->dpcd);
>  }
>  
> +static void
> +intel_dp_check_edp_typec_supp(struct intel_encoder *encoder)

It's not about checking anything, it's about reading, right?

> +{
> +	struct drm_i915_private *i915 = to_i915(encoder->base.dev);
> +	bool is_tc_port = intel_encoder_is_tc(encoder);
> +	u32 ret = 0;
> +
> +	if (encoder->type != INTEL_OUTPUT_EDP || !is_tc_port)

Currently we warn at connector init for eDP type-C combo.

> +		return;
> +
> +	ret = intel_de_read(i915, PICA_PHY_CONFIG_CONTROL);
> +	encoder->typec_supp = ret & EDP_ON_TYPEC;
> +}
> +
>  static int
>  intel_dp_detect(struct drm_connector *connector,
>  		struct drm_modeset_acquire_ctx *ctx,
> @@ -5595,6 +5609,8 @@ intel_dp_detect(struct drm_connector *connector,
>  	if (!intel_display_driver_check_access(dev_priv))
>  		return connector->status;
>  
> +	intel_dp_check_edp_typec_supp(encoder);
> +

Isn't this something that should be determined at intel_ddi_init() time?

BR,
Jani.


>  	/* Can't disconnect eDP */
>  	if (intel_dp_is_edp(intel_dp))
>  		status = edp_detect(intel_dp);
> diff --git a/drivers/gpu/drm/i915/i915_reg.h b/drivers/gpu/drm/i915/i915_reg.h
> index da65500cd0c8..5f5a6ade5f8c 100644
> --- a/drivers/gpu/drm/i915/i915_reg.h
> +++ b/drivers/gpu/drm/i915/i915_reg.h
> @@ -4583,4 +4583,7 @@ enum skl_power_gate {
>  
>  #define MTL_MEDIA_GSI_BASE		0x380000
>  
> +#define PICA_PHY_CONFIG_CONTROL 	_MMIO(0x16FE68)
> +#define   EDP_ON_TYPEC			REG_BIT(31)
> +
>  #endif /* _I915_REG_H_ */

-- 
Jani Nikula, Intel