On Tue, 2020-05-26 at 15:19 -0700, Alex Guzman wrote: [...] > When using your patch, I get a hang when trying to use tpm2_getcap, > and dmesg shows some info. Are you sure it's all applied? This > [ 570.913803] tpm_tcg_write_bytes+0x2f/0x40 > [ 570.913805] release_locality+0x49/0x220 > [ 570.913807] tpm_relinquish_locality+0x1f/0x40 > [ 570.913808] tpm_chip_stop+0x21/0x40 > [ 570.913810] tpm_put_ops+0x9/0x30 > [ 570.913811] tpm_common_write+0x179/0x190 > [ 570.913813] vfs_write+0xb1/0x1a0 Implies an unmatched tpm_put_ops() in the async write path, as though this hunk: > @@ -211,11 +202,19 @@ ssize_t tpm_common_write(struct file *file, > const char __user *buf, > if (file->f_flags & O_NONBLOCK) { > priv->command_enqueued = true; > queue_work(tpm_dev_wq, &priv->async_work); > - tpm_put_ops(priv->chip); > mutex_unlock(&priv->buffer_mutex); > return size; > } Is missing. I actually booted the patch in my TPM based VM and it all seems to work OK when I execute tpm2_getcap (I verified it's using O_NONBLOCK) and tssgetcapability in sync mode. James