github-mirror/linux
1
0
Fork 0
mirror of https://github.com/torvalds/linux.git synced 2026-11-07 06:17:02 +01:00
Code Issues Actions Packages Projects Releases Wiki Activity Graph

ACPI: video: force native backlight on Dell OptiPlex AIO 7410 35W

Browse Source 
The Dell OptiPlex AIO 7410 35W (board 01KP8D) declares DELL0501 in its
ACPI DSDT (status = 0x0F) even though no UART scalar board is physically
present. This causes acpi_video_get_backlight_type() to return
acpi_backlight_dell_uart, which makes i915 skip registering
intel_backlight. The dell-uart-backlight driver then times out talking
to the absent board and the probe fails, leaving the machine with zero
backlight control.

A BIOS update fixes this on some models (e.g. OptiPlex 7420, board
0914RT) by setting DELL0501 _STA to 0, but Dell has not shipped a
corrected BIOS for the 7410 even in the latest release (1.37.0,
2026-05-28).

Add a DMI quirk to force native backlight on this model so that i915
registers intel_backlight and brightness control works out of the box.

Tested on:
  - OptiPlex AIO 7410 35W (01KP8D, BIOS 1.37.0) -- confirmed
    acpi_backlight=native produces working intel_backlight (raw,
    max=96000), DMI quirk has the same effect.
  - OptiPlex AIO 7420 35W (0914RT, BIOS 1.27.0) -- DELL0501 absent in
    updated BIOS, intel_backlight works natively (no regression).

Signed-off-by: Chitransh Mandhaniya <Chitransh_Mandhaniya@dell.com>
Reviewed-by: Hans de Goede <johannes.goede@oss.qualcomm.com>
Link: https://patch.msgid.link/20261010124830.116750-1-chitranshmandhaniya@gmail.com
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
This commit is contained in:
Chitransh Mandhaniya 2026-10-10 18:18:30 +05:30 committed by Rafael J. Wysocki
parent efed63bc78
commit 5d76269ee7
1 changed files with 8 additions and 0 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

8
drivers/acpi/video_detect.c
View File

@ -883,6 +883,14 @@ static const struct dmi_system_id video_detect_dmi_table[] = {
DMI_MATCH(DMI_PRODUCT_NAME, "OptiPlex 7770 AIO"),
},
},
{
.callback = video_detect_force_native,
/* Dell OptiPlex AIO 7410 35W */
.matches = {
DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
DMI_MATCH(DMI_PRODUCT_NAME, "OptiPlex AIO 7410 35W"),
},
},
/*
* Models which have nvidia-ec-wmi support, but should not use it.