From: Hans de Goede <hdegoede@xxxxxxxxxx>
commit 5c7bb62cb8f53de71d8ab3d619be22740da0b837 upstream.
Dell All In One (AIO) models released after 2017 may use a backlight
controller board connected to an UART.
In DSDT this uart port will be defined as:
Name (_HID, "DELL0501")
Name (_CID, EisaId ("PNP0501")
The Dell OptiPlex 7760 AIO has an ACPI device for one if its UARTs with
the above _HID + _CID. Loading the dell-uart-backlight driver shows that
there actually is a backlight controller board attached to the UART,
which reports a firmware version of "G&MX01-V15".
But the backlight controller board does not actually control the backlight
brightness and the GPU's native backlight control method does work.
Add a quirk to use the GPU's native backlight control method on this model.
Fixes: 484bae9e4d6a ("platform/x86: Add new Dell UART backlight driver")
Closes: https://bugzilla.redhat.com/show_bug.cgi?id=2303936
Cc: All applicable <stable@xxxxxxxxxxxxxxx>
Signed-off-by: Hans de Goede <hdegoede@xxxxxxxxxx>
Reviewed-by: Andy Shevchenko <andy@xxxxxxxxxx>
Link: https://patch.msgid.link/20240814190159.15650-4-hdegoede@xxxxxxxxxx
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@xxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
drivers/acpi/video_detect.c | 15 +++++++++++++++
1 file changed, 15 insertions(+)
--- a/drivers/acpi/video_detect.c
+++ b/drivers/acpi/video_detect.c
@@ -808,6 +808,21 @@ static const struct dmi_system_id video_
},
/*
+ * Dell AIO (All in Ones) which advertise an UART attached backlight
+ * controller board in their ACPI tables (and may even have one), but
+ * which need native backlight control nevertheless.
+ */
+ {
+ /* https://bugzilla.redhat.com/show_bug.cgi?id=2303936 */
+ .callback = video_detect_force_native,
+ /* Dell OptiPlex 7760 AIO */
+ .matches = {
+ DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
+ DMI_MATCH(DMI_PRODUCT_NAME, "OptiPlex 7760 AIO"),
+ },
+ },
+
+ /*
* 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.
Patches currently in stable-queue which might be from hdegoede@xxxxxxxxxx are
queue-6.10/acpi-ec-evaluate-_reg-outside-the-ec-scope-more-carefully.patch
queue-6.10/revert-acpi-ec-evaluate-orphan-_reg-under-ec-device.patch
queue-6.10/input-i8042-add-forcenorestore-quirk-to-leave-controller-untouched-even-on-s3.patch
queue-6.10/acpi-video-add-backlight-native-quirk-for-dell-optiplex-7760-aio.patch
queue-6.10/acpi-video-add-dell-uart-backlight-controller-detection.patch
queue-6.10/acpica-add-a-depth-argument-to-acpi_execute_reg_methods.patch
queue-6.10/input-i8042-use-new-forcenorestore-quirk-to-replace-old-buggy-quirk-combination.patch
queue-6.10/platform-x86-dell-uart-backlight-use-acpi_video_get_backlight_type.patch
queue-6.10/usb-misc-ljca-add-lunar-lake-ljca-gpio-hid-to-ljca_gpio_hids.patch
queue-6.10/media-atomisp-fix-streaming-no-longer-working-on-byt-isp2400-devices.patch
