6.11-stable review patch. If anyone has any objections, please let me know.
------------------
From: Hans de Goede hdegoede@redhat.com
commit ac78288fe062b64e45a479eaae74aaaafcc8ecdd 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 5480 AIO has an ACPI device for one of its UARTs with the above _HID + _CID. Loading the dell-uart-backlight driver fails with the following errors:
[ 18.261353] dell_uart_backlight serial0-0: Timed out waiting for response. [ 18.261356] dell_uart_backlight serial0-0: error -ETIMEDOUT: getting firmware version [ 18.261359] dell_uart_backlight serial0-0: probe with driver dell_uart_backlight failed with error -110
Indicating that there is no backlight controller board attached to the UART, while 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: cd8e468efb4f ("ACPI: video: Add Dell UART backlight controller detection") Cc: All applicable stable@vger.kernel.org Signed-off-by: Hans de Goede hdegoede@redhat.com Link: https://patch.msgid.link/20240918153849.37221-1-hdegoede@redhat.com [ rjw: Changelog edit ] Signed-off-by: Rafael J. Wysocki rafael.j.wysocki@intel.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- drivers/acpi/video_detect.c | 9 +++++++++ 1 file changed, 9 insertions(+)
--- a/drivers/acpi/video_detect.c +++ b/drivers/acpi/video_detect.c @@ -845,6 +845,15 @@ static const struct dmi_system_id video_ * which need native backlight control nevertheless. */ { + /* https://github.com/zabbly/linux/issues/26 */ + .callback = video_detect_force_native, + /* Dell OptiPlex 5480 AIO */ + .matches = { + DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."), + DMI_MATCH(DMI_PRODUCT_NAME, "OptiPlex 5480 AIO"), + }, + }, + { /* https://bugzilla.redhat.com/show_bug.cgi?id=2303936 */ .callback = video_detect_force_native, /* Dell OptiPlex 7760 AIO */