From e9cf4d9b9a6fdb1df6401a59f5ac5d24006bfeae Mon Sep 17 00:00:00 2001 From: Dmitry Osipenko Date: Mon, 24 Oct 2022 17:12:10 +0300 Subject: [PATCH] ACPI: video: Fix missing native backlight on Chromebooks Chromebooks don't have backlight in ACPI table, they suppose to use native backlight in this case. Check presence of the CrOS embedded controller ACPI device and prefer the native backlight if EC found. Suggested-by: Hans de Goede Fixes: 2600bfa3df99 ("ACPI: video: Add acpi_video_backlight_use_native() helper") Signed-off-by: Dmitry Osipenko Reviewed-by: Hans de Goede Acked-by: Rafael J. Wysocki Link: https://lore.kernel.org/r/20221024141210.67784-1-dmitry.osipenko@collabora.com Signed-off-by: Hans de Goede --- drivers/acpi/video_detect.c | 12 ++++++++++++ 1 file changed, 12 insertions(+) diff --git a/drivers/acpi/video_detect.c b/drivers/acpi/video_detect.c index 0d9064a9804c..9cd8797d12bb 100644 --- a/drivers/acpi/video_detect.c +++ b/drivers/acpi/video_detect.c @@ -668,6 +668,11 @@ static const struct dmi_system_id video_detect_dmi_table[] = { { }, }; +static bool google_cros_ec_present(void) +{ + return acpi_dev_found("GOOG0004"); +} + /* * Determine which type of backlight interface to use on this system, * First check cmdline, then dmi quirks, then do autodetect. @@ -730,6 +735,13 @@ 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; } -- GitLab