Re: [PATCH 4.19 002/106] tpm: Fix TPM 1.2 Shutdown sequence to prevent future TPM operations

From: Jarkko Sakkinen
Date: Tue Oct 08 2019 - 19:40:22 EST


> > --- a/drivers/char/tpm/tpm-chip.c
> > +++ b/drivers/char/tpm/tpm-chip.c
> > @@ -187,12 +187,13 @@ static int tpm_class_shutdown(struct device *dev)
> > {
> > struct tpm_chip *chip = container_of(dev, struct tpm_chip, dev);
> >
> > + down_write(&chip->ops_sem);
> > if (chip->flags & TPM_CHIP_FLAG_TPM2) {
> > - down_write(&chip->ops_sem);
> > tpm2_shutdown(chip, TPM2_SU_CLEAR);
> > chip->ops = NULL;
> > - up_write(&chip->ops_sem);
> > }
> > + chip->ops = NULL;
> > + up_write(&chip->ops_sem);
> >
> > return 0;
> > }
>
> Still can be improved -- chip->ops = NULL; is done twice, copy inside
> the if {} is redundant...

Thanks. I can update this.

/Jarkko