ACPI: video: Improve Chromebook checks

2 improvements for the Chromebook handling in
acpi_video_get_backlight_type():

1. Also check for the "GOOG000C" ACPI HID used on some models
2. Move the Chromebook check to above the ACPI-video check normally
   Chromebooks don't have ACPI video backlight support, but when
   flashed with upstream coreboot builds they may have ACPI video
   backlight support, but native should still be used/preferred then.

Suggested-by: Mr. Chromebox <mrchromebox@gmail.com>
Signed-off-by: Hans de Goede <hdegoede@redhat.com>

diff --git a/drivers/acpi/video_detect.c b/drivers/acpi/video_detect.c
index 9cd8797..06aaec2 100644 (file)
--- a/drivers/acpi/video_detect.c
+++ b/drivers/acpi/video_detect.c
@@ -670,7 +670,7 @@ 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 +718,10 @@ 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 +739,6 @@ 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;
 }