[PATCH v3 0/2] Save Brightness on Macs

From: Atharva Tiwari

Date: Sun Mar 15 2026 - 18:20:41 EST


We fix this by writing the brightness value to efivar 'backlight-level'
at shutdown only, when it is changed since the last boot.

Changes in v3:
- Fixed a bug, in which apple_brightness_shutdown is still called on
non-supported devices.
Changes in v2:
- Saved the brightness only when it is different than the previous boot.

Link to v2:
https://lore.kernel.org/all/20260315215302.24087-1-atharvatiwarilinuxdev@xxxxxxxxx/
Link to v1:
https://lore.kernel.org/all/20260206125641.12983-1-atharvatiwarilinuxdev@xxxxxxxxx/

Atharva Tiwari (2):
efi: Save Brightness using EFI on Macs
platform/apple-gmux: use apple_brightness to save brightness to EFI

drivers/firmware/efi/Kconfig | 10 +++
drivers/firmware/efi/Makefile | 1 +
drivers/firmware/efi/apple-brightness.c | 67 +++++++++++++++++++
drivers/platform/x86/apple-gmux.c | 21 ++++++
.../linux/platform_data/apple-brightness.h | 20 ++++++
5 files changed, 119 insertions(+)
create mode 100644 drivers/firmware/efi/apple-brightness.c
create mode 100644 include/linux/platform_data/apple-brightness.h

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2.43.0