Re: [Intel-gfx] [RESEND 2/3] drm/i915/dsi: fix dual-link DSI backlight and CABC ports for display 11+

["Lisovskiy, Stanislav" <stanislav.lisovskiy@intel.com>]

On Tue, Aug 16, 2022 at 06:37:21PM +0300, Jani Nikula wrote:
> The VBT dual-link DSI backlight and CABC still use ports A and C, both
> in Bspec and code, while display 11+ DSI only supports ports A and
> B. Assume port C actually means port B for display 11+ when parsing VBT.
> 
> Bspec: 20154
> Closes: https://gitlab.freedesktop.org/drm/intel/-/issues/6476
> Cc: stable@vger.kernel.org
> Signed-off-by: Jani Nikula <jani.nikula@intel.com>

Reviewed-by: Stanislav Lisovskiy <stanislav.lisovskiy@intel.com>

> ---
>  drivers/gpu/drm/i915/display/intel_bios.c | 10 ++++++----
>  1 file changed, 6 insertions(+), 4 deletions(-)
> 
> diff --git a/drivers/gpu/drm/i915/display/intel_bios.c b/drivers/gpu/drm/i915/display/intel_bios.c
> index 51dde5bfd956..198a2f4920cc 100644
> --- a/drivers/gpu/drm/i915/display/intel_bios.c
> +++ b/drivers/gpu/drm/i915/display/intel_bios.c
> @@ -1596,6 +1596,8 @@ static void parse_dsi_backlight_ports(struct drm_i915_private *i915,
>  				      struct intel_panel *panel,
>  				      enum port port)
>  {
> +	enum port port_bc = DISPLAY_VER(i915) >= 11 ? PORT_B : PORT_C;
> +
>  	if (!panel->vbt.dsi.config->dual_link || i915->vbt.version < 197) {
>  		panel->vbt.dsi.bl_ports = BIT(port);
>  		if (panel->vbt.dsi.config->cabc_supported)
> @@ -1609,11 +1611,11 @@ static void parse_dsi_backlight_ports(struct drm_i915_private *i915,
>  		panel->vbt.dsi.bl_ports = BIT(PORT_A);
>  		break;
>  	case DL_DCS_PORT_C:
> -		panel->vbt.dsi.bl_ports = BIT(PORT_C);
> +		panel->vbt.dsi.bl_ports = BIT(port_bc);
>  		break;
>  	default:
>  	case DL_DCS_PORT_A_AND_C:
> -		panel->vbt.dsi.bl_ports = BIT(PORT_A) | BIT(PORT_C);
> +		panel->vbt.dsi.bl_ports = BIT(PORT_A) | BIT(port_bc);
>  		break;
>  	}
>  
> @@ -1625,12 +1627,12 @@ static void parse_dsi_backlight_ports(struct drm_i915_private *i915,
>  		panel->vbt.dsi.cabc_ports = BIT(PORT_A);
>  		break;
>  	case DL_DCS_PORT_C:
> -		panel->vbt.dsi.cabc_ports = BIT(PORT_C);
> +		panel->vbt.dsi.cabc_ports = BIT(port_bc);
>  		break;
>  	default:
>  	case DL_DCS_PORT_A_AND_C:
>  		panel->vbt.dsi.cabc_ports =
> -					BIT(PORT_A) | BIT(PORT_C);
> +					BIT(PORT_A) | BIT(port_bc);
>  		break;
>  	}
>  }
> -- 
> 2.34.1
>