[Intel-gfx] [PATCH 1/3] drm/i915/display: move vbt check to intel_ddi_init()

[Jani Nikula]

On Sat, 13 Feb 2021, Lucas De Marchi <lucas.demarchi at intel.com> wrote:
> On intel_ddi_init() we already check VBT if the port supports HDMI/DP
> and bail out otherwise. Instad of checking if a single port is present
> using VBT in intel_display.c, move the stronger check to
> intel_ddi_init() and return early in case it's not supported.  There
> would be no way intel_bios_* would report support for hdmi/dp if the
> port isn't present so this should cause no regressions for other
> platforms.

Sorry, but this will regress machines that have no VBT.

I've been thinking about creating fake child devices for that case to
reduce the exceptions.

BR,
Jani.



>
> Signed-off-by: Lucas De Marchi <lucas.demarchi at intel.com>
> ---
>  drivers/gpu/drm/i915/display/intel_ddi.c     |  7 +++++++
>  drivers/gpu/drm/i915/display/intel_display.c | 14 ++++++--------
>  2 files changed, 13 insertions(+), 8 deletions(-)
>
> diff --git a/drivers/gpu/drm/i915/display/intel_ddi.c b/drivers/gpu/drm/i915/display/intel_ddi.c
> index 3b97c0091812..1235be0ba5d1 100644
> --- a/drivers/gpu/drm/i915/display/intel_ddi.c
> +++ b/drivers/gpu/drm/i915/display/intel_ddi.c
> @@ -3972,6 +3972,13 @@ void intel_ddi_init(struct drm_i915_private *dev_priv, enum port port)
>  	bool init_hdmi, init_dp;
>  	enum phy phy = intel_port_to_phy(dev_priv, port);
>  
> +	if (!intel_bios_is_port_present(dev_priv, port)) {
> +		drm_dbg_kms(&dev_priv->drm,
> +			    "VBT says port %c is not present, respect it\n",
> +			    port_name(port));
> +		return;
> +	}
> +
>  	/*
>  	 * On platforms with HTI (aka HDPORT), if it's enabled at boot it may
>  	 * have taken over some of the PHYs and made them unavailable to the
> diff --git a/drivers/gpu/drm/i915/display/intel_display.c b/drivers/gpu/drm/i915/display/intel_display.c
> index 23ec68498800..7aaf7a29d493 100644
> --- a/drivers/gpu/drm/i915/display/intel_display.c
> +++ b/drivers/gpu/drm/i915/display/intel_display.c
> @@ -11904,13 +11904,13 @@ static void intel_setup_outputs(struct drm_i915_private *dev_priv)
>  		intel_ddi_init(dev_priv, PORT_C);
>  		intel_ddi_init(dev_priv, PORT_D);
>  		intel_ddi_init(dev_priv, PORT_E);
> +
>  		/*
> -		 * On some ICL SKUs port F is not present. No strap bits for
> -		 * this, so rely on VBT.
> -		 * Work around broken VBTs on SKUs known to have no port F.
> +		 * On some ICL SKUs port F is not present, but broken VBTs mark
> +		 * the port as present. Only try to initialize port F for the
> +		 * SKUs that may actually have it.
>  		 */
> -		if (IS_ICL_WITH_PORT_F(dev_priv) &&
> -		    intel_bios_is_port_present(dev_priv, PORT_F))
> +		if (IS_ICL_WITH_PORT_F(dev_priv))
>  			intel_ddi_init(dev_priv, PORT_F);
>  
>  		icl_dsi_init(dev_priv);
> @@ -11964,10 +11964,8 @@ static void intel_setup_outputs(struct drm_i915_private *dev_priv)
>  		/*
>  		 * On SKL we don't have a way to detect DDI-E so we rely on VBT.
>  		 */
> -		if (IS_GEN9_BC(dev_priv) &&
> -		    intel_bios_is_port_present(dev_priv, PORT_E))
> +		if (IS_GEN9_BC(dev_priv))
>  			intel_ddi_init(dev_priv, PORT_E);
> -
>  	} else if (HAS_PCH_SPLIT(dev_priv)) {
>  		int found;

-- 
Jani Nikula, Intel Open Source Graphics Center