fix: Y-Logo LED GET/SET byte mismatch and IO-Port init on Gen 10#402
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alstergee wants to merge 1 commit intojohnfanv2:mainfrom
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fix: Y-Logo LED GET/SET byte mismatch and IO-Port init on Gen 10#402alstergee wants to merge 1 commit intojohnfanv2:mainfrom
alstergee wants to merge 1 commit intojohnfanv2:mainfrom
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The DSDT WMAF method uses different byte positions for the Y-Logo LED
(LIGHT_ID_YLOGO = 0x03) compared to the keyboard backlight:
Y-Logo GET: state is in result[0] (LCST), result[1] (LCBL) is always 0
Y-Logo SET: DSDT checks byte 1 (SCST) for on/off, ignores byte 2 (SCBL)
EC convention: SCST=1 means ON, SCST=2 means OFF
The driver previously treated all lights the same as the keyboard
backlight (value in byte 2, read from byte 1), causing Y-Logo GET
to always return 0 and SET to always send SCST=1 (always ON).
Also fixes IO-Port LED (LIGHT_ID_IOPORT = 0x05) init failure on
BIOS Q7CN45WW where DSDT returns 0 for unhandled light IDs.
Changed lower_limit from 1 to 0 so the validation check passes.
Tested on Lenovo Legion Pro 7 16IAX10H (83F5) with BIOS Q7CN45WW.
Note: On Spectrum-equipped Gen 10 models, the physical lid logo LED
is actually controlled by the ITE 8258 USB HID controller (048d:c197),
not the WMI/ACPI path. The Y-Logo WMI interface may only be relevant
for non-Spectrum models. The IO-Port LED WMI interface (SLID=5) is
not handled by the DSDT WMAF method at all on this model.
Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>
ChaoticSi1ence
added a commit
to ChaoticSi1ence/legion-pro-7-16iax10h-linux
that referenced
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Mar 1, 2026
DSDT uses different byte positions for Y-Logo (LIGHT_ID_YLOGO = 0x03) vs keyboard backlight: GET: Y-Logo state is in result[0] (LCST), not result[1] (LCBL) SET: DSDT checks byte 1 (SCST) for on/off, EC convention 1=ON 2=OFF The driver treated all lights like keyboard backlight (value in byte 2, read from byte 1), causing Y-Logo GET to always return 0 and SET to never actually turn it off. Based on alstergee's DSDT analysis from upstream PR johnfanv2#402. IO-Port lower_limit fix was already applied in 62ffe9c.
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Thanks for the thorough DSDT analysis and clean fix, @alstergee. The Y-Logo GET/SET byte mismatch is a real bug — the driver was treating all light IDs like the keyboard backlight. I've picked up your Y-Logo fixes in my fork (ChaoticSi1ence/LenovoLegionLinux@3788257). The IO-Port Nice catch on the Spectrum vs WMI distinction for the lid LED too — good to have that documented. |
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Summary
result[0](LCST) forLIGHT_ID_YLOGO, but driver readsresult[1](LCBL) which is hardcoded to 0. Fixed by readingresult[0]whenlight_id == LIGHT_ID_YLOGO.byte[1] = 0x01and puts the brightness inbyte[2](SCBL). Fixed by placing the on/off value in byte 1 with EC convention (1=ON, 2=OFF).LIGHT_ID_IOPORT(0x05) — GET returns 0 from the default GLCS buffer. Thelower_limit=1validation rejects 0, failing init. Changed tolower_limit=0.DSDT Analysis (Q7CN45WW)
The WMAF method handles light IDs differently:
The driver previously treated all light IDs the same as the keyboard backlight.
Hardware note
On Spectrum-equipped Gen 10 models (like the 16IAX10H / 83F5), the physical lid logo LED is controlled by the ITE 8258 USB HID controller (048d:c197) via the Spectrum protocol (
OP_LOGO_STATUS), not the WMI/ACPI path. The WMI Y-Logo interface may only be relevant for non-Spectrum models.Test plan
echo 1 > /sys/class/leds/platform::ylogo/brightness— writes without error, reads back 1echo 0 > /sys/class/leds/platform::ylogo/brightness— writes without error, reads back 0