On Thu, Apr 07, 2016 at 07:36:54AM -0700, Jason Gunthorpe wrote: > I will have to look closer after the conference, but this does not look > right. > > I vaguely recall commenting on this before. Move the shutdown into the > core code to fix it.
This fix that I sent is not the right way to do it. One example scenario: 1. TIS driver gets detached, which causes tpm_tis_remove() to be called. 2. Some in-kernel subsystem uses TPM, which should not be done since the hardware is already unitialized. 3. The devres subsystem sets ops to NULL. Even though the fix is wrong I feel that it might put the rwsem into question. I'm just thinking that maybe there could be a release callback in tpm_class_ops that could be called by tpm_del_char_device(). There can't be clients for the chip at that point so no synchronization mechanism is needed. > Jason /Jarkko
