On my old C720 Chromebook, in the past I have needed to add `GRUB_CMDLINE_LINUX_DEFAULT="tpm_tis.force=1"` to GRUB to enable suspend/resume to work properly in Debian. After a fresh re-install and upgrade to Debian unstable/sid, suspend/resume is not working with kernel 5.2.9-2. System will suspend, but trying to resume results in a hard reboot. I think the problem is with tpm_tis. Messages in the log upon boot ... ``` $ journalctl -b | grep tpm Sep 16 18:18:01 cruithne kernel: tpm_tis tpm_tis: 1.2 TPM (device-id 0xB, rev-id 16) Sep 16 18:18:01 cruithne kernel: tpm tpm0: tpm_try_transmit: send(): error -5 Sep 16 18:18:01 cruithne kernel: tpm tpm0: A TPM error (-5) occurred attempting to determine the timeouts Sep 16 18:18:01 cruithne kernel: tpm_tis tpm_tis: Could not get TPM timeouts and durations Sep 16 18:18:01 cruithne kernel: tpm_tis 00:08: 1.2 TPM (device-id 0xB, rev-id 16) Sep 16 18:18:01 cruithne kernel: tpm tpm0: tpm_try_transmit: send(): error -5 Sep 16 18:18:01 cruithne kernel: tpm tpm0: A TPM error (-5) occurred attempting to determine the timeouts Sep 16 18:18:01 cruithne kernel: tpm_tis 00:08: Could not get TPM timeouts and durations Sep 16 18:18:01 cruithne kernel: tpm_inf_pnp 00:08: Found TPM with ID IFX0102 ``` Suspend/resume *does* continue to work with kernel 4.19.67-2 (current default in Debian stable). Messages in the log ... ``` Sep 16 18:00:38 cruithne kernel: tpm_tis 00:08: 1.2 TPM (device-id 0xB, rev-id 16) Sep 16 18:00:38 cruithne kernel: tpm tpm0: [Firmware Bug]: TPM interrupt not working, polling instead ``` Removing the "tpm_tis.force=1" line from GRUB when booting into kernel 5.2.9-2 makes no difference. A google search with "tpm tpm0" "tpm_try_transmit" "error -5" "A TPM error (-5) occurred attempting to determine the timeouts" returns NO hits. Dropping the last term is a bit more successful but still leads me to no solution. Any ideas how I might get this to work with the latest kernel 5.2*? Thanks in advance! -- Daniel Wayne Armstrong https://www.circuidipity.com <http://www.circuidipity.com> Accomplish the great task by a series of small acts. -- Lao Tzu