Re: [Intel-gfx] [PATCH v2 7/7] drm/i915: Convert HSW/BDW to use port_mask for DDI probe

From: Jani Nikula <jani.nikula@linux.intel.com>
To: Ville Syrjala <ville.syrjala@linux.intel.com>,
	intel-gfx@lists.freedesktop.org
Subject: Re: [Intel-gfx] [PATCH v2 7/7] drm/i915: Convert HSW/BDW to use port_mask for DDI probe
Date: Fri, 02 Jun 2023 17:51:19 +0300	[thread overview]
Message-ID: <87bkhxex3s.fsf@intel.com> (raw)
In-Reply-To: <20230531134806.23065-8-ville.syrjala@linux.intel.com>

On Wed, 31 May 2023, Ville Syrjala <ville.syrjala@linux.intel.com> wrote:
> From: Ville Syrjälä <ville.syrjala@linux.intel.com>
>
> Make HSW/BDW use port_mask for output probing as well.
> To achieve that the strap checks are moved into
> intel_ddi_init() itself. Or should we move them to the
> runtime port_mask init instead? Maybe not since the hardware
> is still there, just not connected to anything.
>
> v2: Account for DDI-E in strap detection
>     Keep to the old CRT->DDI init order
>
> Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
> ---
>  drivers/gpu/drm/i915/display/intel_ddi.c     | 29 ++++++++++++++++++++
>  drivers/gpu/drm/i915/display/intel_display.c | 23 +++-------------
>  2 files changed, 33 insertions(+), 19 deletions(-)
>
> diff --git a/drivers/gpu/drm/i915/display/intel_ddi.c b/drivers/gpu/drm/i915/display/intel_ddi.c
> index 31001b9a29b0..d89a9b85a780 100644
> --- a/drivers/gpu/drm/i915/display/intel_ddi.c
> +++ b/drivers/gpu/drm/i915/display/intel_ddi.c
> @@ -4657,6 +4657,29 @@ static void intel_ddi_tc_encoder_shutdown_complete(struct intel_encoder *encoder
>  #define port_tc_name(port) ((port) - PORT_TC1 + '1')
>  #define tc_port_name(tc_port) ((tc_port) - TC_PORT_1 + '1')
>  
> +static bool port_strap_detected(struct drm_i915_private *i915, enum port port)
> +{
> +	/* straps not used on skl+ */
> +	if (DISPLAY_VER(i915) >= 9)
> +		return true;
> +
> +	switch (port) {
> +	case PORT_A:
> +		return intel_de_read(i915, DDI_BUF_CTL(PORT_A)) & DDI_INIT_DISPLAY_DETECTED;
> +	case PORT_B:
> +		return intel_de_read(i915, SFUSE_STRAP) & SFUSE_STRAP_DDIB_DETECTED;
> +	case PORT_C:
> +		return intel_de_read(i915, SFUSE_STRAP) & SFUSE_STRAP_DDIC_DETECTED;
> +	case PORT_D:
> +		return intel_de_read(i915, SFUSE_STRAP) & SFUSE_STRAP_DDID_DETECTED;
> +	case PORT_E:
> +		return true; /* no strap for DDI-E */
> +	default:
> +		MISSING_CASE(port);
> +		return false;
> +	}
> +}
> +
>  void intel_ddi_init(struct drm_i915_private *dev_priv, enum port port)
>  {
>  	struct intel_digital_port *dig_port;
> @@ -4665,6 +4688,12 @@ 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 (!port_strap_detected(dev_priv, port)) {
> +		drm_dbg_kms(&dev_priv->drm,
> +			    "Port %c strap not detected\n", port_name(port));
> +		return;
> +	}
> +
>  	if (!assert_port_valid(dev_priv, port))
>  		return;

I might have put this check first before the straps, so we get the
invalid port message for bogus ports instead of MISSING_CASE().

Either way,

Reviewed-by: Jani Nikula <jani.nikula@intel.com>

>  
> diff --git a/drivers/gpu/drm/i915/display/intel_display.c b/drivers/gpu/drm/i915/display/intel_display.c
> index 12f2e3897595..1ae4854b275e 100644
> --- a/drivers/gpu/drm/i915/display/intel_display.c
> +++ b/drivers/gpu/drm/i915/display/intel_display.c
> @@ -7387,9 +7387,12 @@ void intel_setup_outputs(struct drm_i915_private *dev_priv)
>  	if (!HAS_DISPLAY(dev_priv))
>  		return;
>  
> -	if (DISPLAY_VER(dev_priv) >= 9) {
> +	if (HAS_DDI(dev_priv)) {
>  		enum port port;
>  
> +		if (intel_ddi_crt_present(dev_priv))
> +			intel_crt_init(dev_priv);
> +
>  		for_each_port_masked(port, DISPLAY_RUNTIME_INFO(dev_priv)->port_mask)
>  			intel_ddi_init(dev_priv, port);
>  
> @@ -7400,24 +7403,6 @@ void intel_setup_outputs(struct drm_i915_private *dev_priv)
>  
>  		if (IS_GEMINILAKE(dev_priv) || IS_BROXTON(dev_priv))
>  			vlv_dsi_init(dev_priv);
> -	} else if (HAS_DDI(dev_priv)) {
> -		u32 found;
> -
> -		if (intel_ddi_crt_present(dev_priv))
> -			intel_crt_init(dev_priv);
> -
> -		/* Haswell uses DDI functions to detect digital outputs. */
> -		found = intel_de_read(dev_priv, DDI_BUF_CTL(PORT_A)) & DDI_INIT_DISPLAY_DETECTED;
> -		if (found)
> -			intel_ddi_init(dev_priv, PORT_A);
> -
> -		found = intel_de_read(dev_priv, SFUSE_STRAP);
> -		if (found & SFUSE_STRAP_DDIB_DETECTED)
> -			intel_ddi_init(dev_priv, PORT_B);
> -		if (found & SFUSE_STRAP_DDIC_DETECTED)
> -			intel_ddi_init(dev_priv, PORT_C);
> -		if (found & SFUSE_STRAP_DDID_DETECTED)
> -			intel_ddi_init(dev_priv, PORT_D);
>  	} else if (HAS_PCH_SPLIT(dev_priv)) {
>  		int found;

-- 
Jani Nikula, Intel Open Source Graphics Center