[Bug 2161011] Re: MSI Prestige 14 H: ELAN I2C touchpad stops working after NVIDIA runtime suspend (nouveau)

Thanks for taking the time to report this bug and helping to make Ubuntu better. We appreciate the difficulties you are facing, but this appears to be a "regular" (non-security) bug. I have unmarked it as a security issue since this bug does not show evidence of allowing attackers to cross privilege boundaries nor directly cause loss of data/privacy. Please feel free to report any other bugs you may find. ** Information type changed from Private Security to Public -- You received this bug notification because you are subscribed to linux in Ubuntu. Matching subscriptions: Bgg, Bmail, Nb https://bugs.launchpad.net/bugs/2161011 Title: MSI Prestige 14 H: ELAN I2C touchpad stops working after NVIDIA runtime suspend (nouveau) Status in linux package in Ubuntu: New Bug description: Hardware Laptop: MSI Prestige 14 H B13UCX-632NEU Mainboard: MS-14F1 BIOS: E14F1IMS.513 2024-03-28 Operating System: Ubuntu 24.04 LTS Kernel: 6.8.0-134-generic Graphics: - Intel Raptor Lake-P UHD Graphics - NVIDIA GeForce RTX 2050 (GA107M) - nouveau driver Touchpad: ELAN0307:00 Vendor/Product ID: 04F3:3282 Driver: i2c_hid_acpi + hid_multitouch Problem The ELAN touchpad works normally immediately after boot. Approximately 10-20 seconds after the graphical session starts, the touchpad stops responding completely. The touchpad is still detected correctly by the kernel and by libinput, but it no longer generates any pointer events. An external USB mouse continues to work normally. Investigation The following was verified: - Touchpad hardware is functional. - The problem is reproducible after every reboot. - i2c_hid_acpi and hid_multitouch are loaded correctly. - libinput detects the touchpad normally. - Runtime power management for the touchpad itself is already disabled. - The problem is not caused by the USB mouse. The problem appears to be related to NVIDIA runtime power management. When the NVIDIA device 0000:01:00.0 enters runtime suspend, the touchpad stops generating events. The following command alone is NOT sufficient: echo on > /sys/bus/pci/devices/0000:01:00.0/power/control However, the following sequence restores the touchpad immediately and is reproducible every time: echo auto > /sys/bus/pci/devices/0000:01:00.0/power/control sleep 2 echo on > /sys/bus/pci/devices/0000:01:00.0/power/control Immediately after this transition the touchpad starts working again. A permanent workaround was implemented using a systemd service which performs this sequence approximately 10 seconds after the graphical session starts. After this workaround the touchpad works reliably. Expected behaviour Runtime power management of the NVIDIA GPU should not cause the ELAN I2C HID touchpad to stop generating input events. Additional observations This appears to be an interaction between: - nouveau runtime power management - NVIDIA PCI runtime suspend - MSI firmware / ACPI - Intel I2C controller - ELAN I2C HID touchpad rather than a failure of the touchpad driver itself. The issue is fully reproducible on every boot. If additional logs or testing are needed, I am willing to help reproduce the issue and test proposed fixes. To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/linux/+bug/2161011/+subscriptions