Commit ac78288f authored by Hans de Goede's avatar Hans de Goede Committed by Rafael J. Wysocki
Browse files

ACPI: video: Add backlight=native quirk for Dell OptiPlex 5480 AIO 



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: cd8e468e ("ACPI: video: Add Dell UART backlight controller detection")
Cc: All applicable <stable@vger.kernel.org>
Signed-off-by: default avatarHans de Goede <hdegoede@redhat.com>
Link: https://patch.msgid.link/20240918153849.37221-1-hdegoede@redhat.com


[ rjw: Changelog edit ]
Signed-off-by: default avatarRafael J. Wysocki <rafael.j.wysocki@intel.com>
parent 9852d85e

drivers/acpi/video_detect.c

+9 −0
Original line number Diff line number Diff line
@@ -844,6 +844,15 @@ static const struct dmi_system_id video_detect_dmi_table[] = { 
	 * controller board in their ACPI tables (and may even have one), but

	 * 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,