I have been encountering a persistent problem with my modem and the suspend/resume functionality on my Linux system running Kernel version 6.1. I have already searched for solutions in various forums and bug trackers, but unfortunately, I haven't found a resolution or response to a similar issue. Therefore, I am reaching out to the Ask Ubuntu community in the hopes of finding a solution or receiving guidance on troubleshooting steps.
The problem I'm experiencing is as follows: When I set my notebook to deep sleep mode, the system is able to suspend successfully on the first attempt. However, subsequent attempts to suspend the system result in an error related to the modem. The error message in the kernel logs indicates:
[ 375.151668] mtk_t7xx 0000:2c:00.0: [PM] Exiting suspend, modem in invalid state
[ 375.151680] mtk_t7xx 0000:2c:00.0: PM: pci_pm_suspend(): t7xx_pci_pm_suspend+0x0/0x20 [mtk_t7xx] returns -14
[ 375.151719] mtk_t7xx 0000:2c:00.0: PM: dpm_run_callback(): pci_pm_suspend+0x0/0x1b0 returns -14
[ 375.151736] mtk_t7xx 0000:2c:00.0: PM: failed to suspend async: error -14
[ 375.152120] PM: Some devices failed to suspend, or early wake event detected
Steps I have taken so far to resolve the issue:
Updated the kernel to the latest available versions.
Checked for BIOS updates for my notebook model, but none were available.
Disabled power management for the modem using the "options mtk_t7xx power_save=0" configuration, but the issue persisted.
I have also discovered an existing bug report related to this problem, but it has gone unanswered for an extended period. I also write to linux kernel mailing list with no response.
Notebook model: Asus expertbook B2
Modem model: Fibocom FM350_GL (mtk_t7xx driver)
Linux distribution: Ubuntu 22.04 LTS
Kernel version: Linux 6.1_OEM
