1 files changed, 32 insertions, 9 deletions

diff --git a/drivers/acpi/video_detect.c b/drivers/acpi/video_detect.c
index 9cd8797d12bb..b2a616287638 100644
--- a/drivers/acpi/video_detect.c
+++ b/drivers/acpi/video_detect.c
@@ -646,6 +646,20 @@ static const struct dmi_system_id video_detect_dmi_table[] = {
 	},
 
 	/*
+	 * Models which have nvidia-ec-wmi support, but should not use it.
+	 * Note this indicates a likely firmware bug on these models and should
+	 * be revisited if/when Linux gets support for dynamic mux mode.
+	 */
+	{
+	 .callback = video_detect_force_native,
+	 /* Dell G15 5515 */
+	 .matches = {
+		DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
+		DMI_MATCH(DMI_PRODUCT_NAME, "Dell G15 5515"),
+		},
+	},
+
+	/*
 	 * Desktops which falsely report a backlight and which our heuristics
 	 * for this do not catch.
 	 */
@@ -670,7 +684,7 @@ static const struct dmi_system_id video_detect_dmi_table[] = {
 
 static bool google_cros_ec_present(void)
 {
-	return acpi_dev_found("GOOG0004");
+	return acpi_dev_found("GOOG0004") || acpi_dev_found("GOOG000C");
 }
 
 /*
@@ -718,6 +732,10 @@ static enum acpi_backlight_type __acpi_video_get_backlight_type(bool native)
 	if (apple_gmux_present())
 		return acpi_backlight_apple_gmux;
 
+	/* Chromebooks should always prefer native backlight control. */
+	if (google_cros_ec_present() && native_available)
+		return acpi_backlight_native;
+
 	/* On systems with ACPI video use either native or ACPI video. */
 	if (video_caps & ACPI_VIDEO_BACKLIGHT) {
 		/*
@@ -735,13 +753,6 @@ static enum acpi_backlight_type __acpi_video_get_backlight_type(bool native)
 			return acpi_backlight_video;
 	}
 
-	/*
-	 * Chromebooks that don't have backlight handle in ACPI table
-	 * are supposed to use native backlight if it's available.
-	 */
-	if (google_cros_ec_present() && native_available)
-		return acpi_backlight_native;
-
 	/* No ACPI video (old hw), use vendor specific fw methods. */
 	return acpi_backlight_vendor;
 }
@@ -754,6 +765,18 @@ EXPORT_SYMBOL(acpi_video_get_backlight_type);
 
 bool acpi_video_backlight_use_native(void)
 {
-	return __acpi_video_get_backlight_type(true) == acpi_backlight_native;
+	/*
+	 * Call __acpi_video_get_backlight_type() to let it know that
+	 * a native backlight is available.
+	 */
+	__acpi_video_get_backlight_type(true);
+
+	/*
+	 * For now just always return true. There is a whole bunch of laptop
+	 * models where (video_caps & ACPI_VIDEO_BACKLIGHT) is false causing
+	 * __acpi_video_get_backlight_type() to return vendor, while these
+	 * models only have a native backlight control.
+	 */
+	return true;
 }
 EXPORT_SYMBOL(acpi_video_backlight_use_native);