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SubjectRe: [PATCH] tpm_tis: turn on TPM before calling tpm_get_timeouts
On Thu, Nov 14, 2019 at 06:49:49PM +0200, Jarkko Sakkinen wrote:
> On Tue, Nov 12, 2019 at 04:26:23PM -0400, Jason Gunthorpe wrote:
> > On Tue, Nov 12, 2019 at 01:23:33PM -0700, Jerry Snitselaar wrote:
> > > On Tue, Nov 12, 2019 at 1:03 PM Jarkko Sakkinen
> > > <jarkko.sakkinen@linux.intel.com> wrote:
> > > >
> > > > On Mon, Nov 11, 2019 at 04:34:18PM -0700, Jerry Snitselaar wrote:
> > > > > With power gating moved out of the tpm_transmit code we need
> > > > > to power on the TPM prior to calling tpm_get_timeouts.
> > > > >
> > > > > Cc: Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com>
> > > > > Cc: Peter Huewe <peterhuewe@gmx.de>
> > > > > Cc: Jason Gunthorpe <jgg@ziepe.ca>
> > > > > Cc: linux-kernel@vger.kernel.org
> > > > > Cc: linux-stable@vger.kernel.org
> > > > > Fixes: a3fbfae82b4c ("tpm: take TPM chip power gating out of tpm_transmit()")
> > > > > Reported-by: Christian Bundy <christianbundy@fraction.io>
> > > > > Signed-off-by: Jerry Snitselaar <jsnitsel@redhat.com>
> > > > > drivers/char/tpm/tpm_tis_core.c | 3 ++-
> > > > > 1 file changed, 2 insertions(+), 1 deletion(-)
> > > > >
> > > > > diff --git a/drivers/char/tpm/tpm_tis_core.c b/drivers/char/tpm/tpm_tis_core.c
> > > > > index 270f43acbb77..cb101cec8f8b 100644
> > > > > +++ b/drivers/char/tpm/tpm_tis_core.c
> > > > > @@ -974,13 +974,14 @@ int tpm_tis_core_init(struct device *dev, struct tpm_tis_data *priv, int irq,
> > > > > * to make sure it works. May as well use that command to set the
> > > > > * proper timeouts for the driver.
> > > > > */
> > > > > + tpm_chip_start(chip);
> > > > > if (tpm_get_timeouts(chip)) {
> > > > > dev_err(dev, "Could not get TPM timeouts and durations\n");
> > > > > rc = -ENODEV;
> > > > > + tpm_stop_chip(chip);
> > > > > goto out_err;
> > > > > }
> > > >
> > > > Couldn't this call just be removed?
> > > >
> > > > /Jarkko
> > > >
> > >
> > > Probably. It will eventually get called when tpm_chip_register
> > > happens. I don't know what the reason was for trying it prior to the
> > > irq probe.
> >
> > At least tis once needed the timeouts before registration because it
> > was issuing TPM commands to complete its setup.
> >
> > If timeouts have not been set then no TPM command should be executed.
>
> Not true since you need a TPM command to set them. That is why they
> have been set initially to maximum possible values.

getting timeouts is the exception

Jason

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