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

Message ID 20240918153849.37221-1-hdegoede@redhat.com
State New
Headers show
Series ACPI: video: Add backlight=native quirk for Dell OptiPlex 5480 AIO | expand

Commit Message

Hans de Goede Sept. 18, 2024, 3:38 p.m. UTC
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 if 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>
---
 drivers/acpi/video_detect.c | 9 +++++++++
 1 file changed, 9 insertions(+)
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Patch

diff --git a/drivers/acpi/video_detect.c b/drivers/acpi/video_detect.c
index b70e84e8049a..015bd8e66c1c 100644
--- a/drivers/acpi/video_detect.c
+++ b/drivers/acpi/video_detect.c
@@ -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,