On Wed, Dec 11, 2019 at 07:52:02PM +0200, Jarkko Sakkinen wrote:
On Tue, Dec 10, 2019 at 01:17:51PM -0800, Tadeusz Struk wrote:
When an application sends TPM commands in NONBLOCKING mode the driver holds chip->tpm_mutex returning from write(), which triggers WARNING: lock held when returning to user space! To silence this warning the driver needs to release the mutex and acquire it again in tpm_dev_async_work() before sending the command.
This commit message is nonsense ATM. The code leaves locks held, which is unacceptable.
Silencing warnings is worst possible rationale for a code change that I can think of starting from the fact that is straight out wrong and malicious.
The code change, however, seems to be doing the right thing.
Please bundle it with the test and fix the commit message appropriately.
/Jarkko