drm/i915/ddi: gracefully handle errors from intel_ddi_init_hdmi_connector()

Errors from intel_ddi_init_hdmi_connector() can just mean "there's no
HDMI" while we'll still want to continue with DP only. Handle the errors
gracefully, but don't propagate. Clear the hdmi_reg which is used as a
proxy to indicate the HDMI is initialized.

v2: Gracefully handle but do not propagate

Cc: Sergey Senozhatsky <senozhatsky@chromium.org>
Cc: Ville Syrjala <ville.syrjala@linux.intel.com>
Reported-and-tested-by: Sergey Senozhatsky <senozhatsky@chromium.org>
Closes: https://lore.kernel.org/r/20241031105145.2140590-1-senozhatsky@chromium.org
Reviewed-by: Sergey Senozhatsky <senozhatsky@chromium.org> # v1
Reviewed-by: Suraj Kandpal <suraj.kandpal@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/d72cb54ac7cc5ca29b3b9d70e4d368ea41643b08.1735568047.git.jani.nikula@intel.com
Signed-off-by: Jani Nikula <jani.nikula@intel.com>

Author: jnikula

drivers/gpu/drm/i915/display/intel_ddi.c

@@ -4757,7 +4757,16 @@ static int intel_ddi_init_hdmi_connector(struct intel_digital_port *dig_port)
 		return -ENOMEM;
 
 	dig_port->hdmi.hdmi_reg = DDI_BUF_CTL(port);
-	intel_hdmi_init_connector(dig_port, connector);
+
+	if (!intel_hdmi_init_connector(dig_port, connector)) {
+		/*
+		 * HDMI connector init failures may just mean conflicting DDC
+		 * pins or not having enough lanes. Handle them gracefully, but
+		 * don't fail the entire DDI init.
+		 */
+		dig_port->hdmi.hdmi_reg = INVALID_MMIO_REG;
+		kfree(connector);
+	}
 
 	return 0;
 }