[Intel-gfx] [PATCH 1/3] drm/i915: Fix VBT DSI DVO port handling

[Ville Syrjala <ville.syrjala@linux.intel.com>]

From: Ville Syrjälä <ville.syrjala@linux.intel.com>

Turns out modern (icl+) VBTs still declare their DSI ports
as MIPI-A and MIPI-C despite the PHYs now being A and B.
Remap appropriately to allow the panels declared as MIPI-C
to work.

Closes: https://gitlab.freedesktop.org/drm/intel/-/issues/8016
Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
---
 drivers/gpu/drm/i915/display/intel_bios.c | 33 ++++++++++++++++-------
 1 file changed, 23 insertions(+), 10 deletions(-)

diff --git a/drivers/gpu/drm/i915/display/intel_bios.c b/drivers/gpu/drm/i915/display/intel_bios.c
index e6ca51232dcf..06a2d98d2277 100644
--- a/drivers/gpu/drm/i915/display/intel_bios.c
+++ b/drivers/gpu/drm/i915/display/intel_bios.c
@@ -2467,6 +2467,22 @@ static enum port dvo_port_to_port(struct drm_i915_private *i915,
 					  dvo_port);
 }
 
+static enum port
+dsi_dvo_port_to_port(struct drm_i915_private *i915, u8 dvo_port)
+{
+	switch (dvo_port) {
+	case DVO_PORT_MIPIA:
+		return PORT_A;
+	case DVO_PORT_MIPIC:
+		if (DISPLAY_VER(i915) >= 11)
+			return PORT_B;
+		else
+			return PORT_C;
+	default:
+		return PORT_NONE;
+	}
+}
+
 static int parse_bdb_230_dp_max_link_rate(const int vbt_max_link_rate)
 {
 	switch (vbt_max_link_rate) {
@@ -3442,19 +3458,16 @@ bool intel_bios_is_dsi_present(struct drm_i915_private *i915,
 
 		dvo_port = child->dvo_port;
 
-		if (dvo_port == DVO_PORT_MIPIA ||
-		    (dvo_port == DVO_PORT_MIPIB && DISPLAY_VER(i915) >= 11) ||
-		    (dvo_port == DVO_PORT_MIPIC && DISPLAY_VER(i915) < 11)) {
-			if (port)
-				*port = dvo_port - DVO_PORT_MIPIA;
-			return true;
-		} else if (dvo_port == DVO_PORT_MIPIB ||
-			   dvo_port == DVO_PORT_MIPIC ||
-			   dvo_port == DVO_PORT_MIPID) {
+		if (dsi_dvo_port_to_port(i915, dvo_port) == PORT_NONE) {
 			drm_dbg_kms(&i915->drm,
 				    "VBT has unsupported DSI port %c\n",
 				    port_name(dvo_port - DVO_PORT_MIPIA));
+			continue;
 		}
+
+		if (port)
+			*port = dsi_dvo_port_to_port(i915, dvo_port);
+		return true;
 	}
 
 	return false;
@@ -3539,7 +3552,7 @@ bool intel_bios_get_dsc_params(struct intel_encoder *encoder,
 		if (!(child->device_type & DEVICE_TYPE_MIPI_OUTPUT))
 			continue;
 
-		if (child->dvo_port - DVO_PORT_MIPIA == encoder->port) {
+		if (dsi_dvo_port_to_port(i915, child->dvo_port) == encoder->port) {
 			if (!devdata->dsc)
 				return false;
 
-- 
2.39.1