Re: [PATCH 1/5] tpm: add functions to set and unset the tpm chips reset state

From: Jason Gunthorpe
Date: Thu Apr 07 2022 - 10:26:35 EST


On Thu, Apr 07, 2022 at 01:18:45PM +0200, Lino Sanfilippo wrote:
> Currently it is not possible to set the tpm chips reset state from within
> the driver. This is problematic if the chip is still in reset after the
> system comes up. This may e.g. happen if the reset line is pulled into
> reset state by a pin configuration in the device tree.

This kind of system is badly misdesigned.

TPM PCRs fundementally cannot work if the TPM reset line is under
software control.

Jason