drm/privacy-screen: Use connector name in lookup

ATM the drm privacy-screen code is not using connector names to lookup
drm privacy-screen providers, drm_privacy_screen_get() does support this,
but before this change the con_id is set to NULL everywhere which is
treated as a wildcard.

There are some worries that we may see devices with 2 displays with
a privacy-screen, be it 2 internal displays or 1 internal + 1 external.

All laptop-models which currently are supported by the drm_privacy_screen
code use an eDP display connected to eDP-1.

This commits enables the use of the con_id parameter, hardcoding this to
"eDP-1" in the lookup tables in drivers/gpu/drm/drm_privacy_screen_x86.c
and adjusting the i915 driver to match.

Using the con_id parameter paves the way for potentially having another
display (attached to a different connector) which also has a builtin
privacy-screen.

This was tested by Hans de Goede on a ThinkPad and by Rajat Jain on
an Intel Chromebook (both with builtin privacy-screens).

Cc: Sean Paul <seanpaul@chromium.org>
Cc: Rajat Jain <rajatja@google.com>
Tested-by: Rajat Jain <rajatja@google.com>
Signed-off-by: Hans de Goede <hdegoede@redhat.com>

drivers/gpu/drm/drm_privacy_screen_x86.c

@@ -62,7 +62,7 @@ static const struct arch_init_data arch_init_data[] __initconst = {
 	{
 		.lookup = {
 			.dev_id = NULL,
-			.con_id = NULL,
+			.con_id = "eDP-1",
 			.provider = "privacy_screen-thinkpad_acpi",
 		},
 		.detect = detect_thinkpad_privacy_screen,
@@ -72,7 +72,7 @@ static const struct arch_init_data arch_init_data[] __initconst = {
 	{
 		.lookup = {
 			.dev_id = NULL,
-			.con_id = NULL,
+			.con_id = "eDP-1",
 			.provider = "privacy_screen-GOOG0010:00",
 		},
 		.detect = detect_chromeos_privacy_screen,

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

@@ -4394,7 +4394,7 @@ intel_ddi_init_dp_connector(struct intel_digital_port *dig_port)
 		struct drm_device *dev = dig_port->base.base.dev;
 		struct drm_privacy_screen *privacy_screen;
 
-		privacy_screen = drm_privacy_screen_get(dev->dev, NULL);
+		privacy_screen = drm_privacy_screen_get(dev->dev, connector->base.name);
 		if (!IS_ERR(privacy_screen)) {
 			drm_connector_attach_privacy_screen_provider(&connector->base,
 								     privacy_screen);

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

@@ -58,7 +58,11 @@
 
 bool intel_display_driver_probe_defer(struct pci_dev *pdev)
 {
+	static const char * const internal_panel_connector_names[] = {
+		"eDP-1",
+	};
 	struct drm_privacy_screen *privacy_screen;
+	int i;
 
 	/*
 	 * apple-gmux is needed on dual GPU MacBook Pro
@@ -68,11 +72,14 @@ bool intel_display_driver_probe_defer(struct pci_dev *pdev)
 		return true;
 
 	/* If the LCD panel has a privacy-screen, wait for it */
-	privacy_screen = drm_privacy_screen_get(&pdev->dev, NULL);
-	if (IS_ERR(privacy_screen) && PTR_ERR(privacy_screen) == -EPROBE_DEFER)
-		return true;
+	for (i = 0; i < ARRAY_SIZE(internal_panel_connector_names); i++) {
+		privacy_screen = drm_privacy_screen_get(&pdev->dev,
+							internal_panel_connector_names[i]);
+		if (IS_ERR(privacy_screen) && PTR_ERR(privacy_screen) == -EPROBE_DEFER)
+			return true;
 
-	drm_privacy_screen_put(privacy_screen);
+		drm_privacy_screen_put(privacy_screen);
+	}
 
 	return false;
 }