Comment 23 for bug 1990700

Update: I recently switched back from Fedora (36?) that was successfully suspending with a manually installed kernel update (preventing other auto updates).
I am currently running Ubuntu 22.04 with a fresh install, suspend is failing.
Kernels tested:
5.1.17 (default) - Doesn't display modem
6.3.3 (latest available mainline) - Grub output displayed "mtk_t7xx .... : Port AT is not opened, drop packets" and hung there, not booting
6.1.0 Briefly displayed this error but booted. Displays modem in network manager, offers 3G,4G,5G in settings.
After a clean boot and attempted suspend I have the following output:

journalctl | grep t7xx:

May 19 11:12:16 host kernel: mtk_t7xx 0000:08:00.0: enabling device (0000 -> 0002)
May 19 11:12:16 hostname kernel: mtk_t7xx 0000:08:00.0: Port AT is not opened, drop packets
May 19 11:12:56 hostname kernel: mtk_t7xx 0000:08:00.0: [PM] SAP suspend error: -110
May 19 11:12:56 hostname kernel: mtk_t7xx 0000:08:00.0: PM: pci_pm_suspend(): t7xx_pci_pm_suspend+0x0/0x20 [mtk_t7xx] returns -110
May 19 11:12:56 hostname kernel: mtk_t7xx 0000:08:00.0: PM: dpm_run_callback(): pci_pm_suspend+0x0/0x1b0 returns -110
May 19 11:12:56 hostname kernel: mtk_t7xx 0000:08:00.0: PM: failed to suspend async: error -110
May 19 11:12:59 hostname kernel: mtk_t7xx 0000:08:00.0: [PM] SAP suspend error: -110
May 19 11:12:59 hostname kernel: mtk_t7xx 0000:08:00.0: PM: pci_pm_suspend(): t7xx_pci_pm_suspend+0x0/0x20 [mtk_t7xx] returns -110
May 19 11:12:59 hostname kernel: mtk_t7xx 0000:08:00.0: PM: dpm_run_callback(): pci_pm_suspend+0x0/0x1b0 returns -110
May 19 11:12:59 hostname kernel: mtk_t7xx 0000:08:00.0: PM: failed to suspend async: error -110

Are there specific kernel versions that have the fix (eg there was a regression) or is there other information/logs I can provide to help?