drm/i915/dsi: fix dual-link DSI backlight and CABC ports for display 11+

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>
Link: https://patchwork.freedesktop.org/patch/msgid/8c462718bcc7b36a83e09d0a5eef058b6bc8b1a2.1660664162.git.jani.nikula@intel.com

diff --git a/drivers/gpu/drm/i915/display/intel_bios.c b/drivers/gpu/drm/i915/display/intel_bios.c
index 51dde5b..198a2f4 100644 (file)
--- 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;
        }
 }