Public bug reported:
## Hardware
* Device: Lenovo Yoga Slim 7 15ILL9
* BIOS: NYCN76WW (April 2026)
* CPU/GPU: Intel Lunar Lake
* GPU driver: xe
* RAM: 32 GB
## Software
* Ubuntu 24.04.4 LTS
* Kernel: 6.17.0-23-generic
## Suspend mode
Only `s2idle` is available: cat /sys/power/mem_sleep
[s2idle]
No `deep` / S3 suspend is exposed by firmware.
---
# Problem description
Suspend and resume generally work, however after resume the system
appears to remain partially stuck in suspend state.
Observed symptoms after resume:
* Power LED continues blinking as if system is still suspended
* Keyboard backlight no longer works
* Fn+Space no longer changes keyboard backlight state
* System itself remains usable
* Previously occasional freezes occurred; suspend/resume sometimes temporarily
fixed them
The issue is fully reproducible.
---
# Diagnostics already performed
## BIOS update
Updated BIOS from older release to:
* NYCN76WW (April 2026)
No behavioral change.
---
## Kernel parameters tested
Current kernel command line: quiet splash xe.enable_psr=0 xe.enable_dc=0
xe.enable_fbc=0 xe.enable_sagv=0
Previously tested and removed:
* acpi_osi overrides
* i915.* parameters
No improvement.
---
## xe driver power features disabled
Verified:
cat /sys/module/xe/parameters/enable_psr
0
cat /sys/module/xe/parameters/enable_dc
0
cat /sys/module/xe/parameters/enable_fbc
0
Issue persists.
---
## EC / keyboard backlight diagnostics
Device still exists after resume:
ls /sys/class/leds/platform::kbd_backlight
Brightness writes succeed:
echo 2 | sudo tee /sys/class/leds/platform::kbd_backlight/brightness
But hardware does not react.
This suggests:
* Linux LED subsystem remains functional
* sysfs interface remains functional
* EC no longer processes hardware commands after resume
---
## Lenovo platform modules loaded
ideapad_laptop
lenovo_wmi_hotkey_utilities
lenovo_wmi_other
lenovo_wmi_gamezone
Reloading `ideapad_laptop` after resume does not restore functionality:
sudo modprobe -r ideapad_laptop
sudo modprobe ideapad_laptop
Keyboard backlight still non-functional afterwards.
---
# Assessment
This appears to be an EC/ACPI/S0ix resume issue rather than a GPU
rendering issue.
Evidence:
* System resumes and remains usable
* LED subsystem stays operational
* EC-controlled hardware remains stuck in suspend state
* Power LED continues suspend blinking pattern
* Keyboard backlight commands are accepted by kernel but ignored by hardware
Likely affected areas:
* ACPI EC resume
* Lenovo WMI/EC synchronization
* S0ix exit path
* platform/x86 Lenovo integration
** Affects: linux (Ubuntu)
Importance: Undecided
Status: New
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https://bugs.launchpad.net/bugs/2152706
Title:
Suspend/Resume EC failure on Lenovo Yoga Slim 7 15ILL9 (Lunar Lake)
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