Re: [PATCH v11 13/14] tpm, tpm_tis: startup chip before testing for interrupts

Jarkko Sakkinen
2022-12-04T17:02:56Z

On Mon, Nov 28, 2022 at 01:53:35PM +0100, Lino Sanfilippo wrote:
>
> On 24.11.22 14:55, Lino Sanfilippo wrote:
> > From: Lino Sanfilippo <l.sanfilippo@kunbus.com>
> >
> > In tpm_tis_gen_interrupt() a request for a property value is sent to the
> > TPM to test if interrupts are generated. However after a power cycle the
> > TPM responds with TPM_RC_INITIALIZE which indicates that the TPM is not
> > yet properly initialized.
> > Fix this by first starting the TPM up before the request is sent. For this
> > the startup implementation is removed from tpm_chip_register() and put
> > into the new function tpm_chip_startup() which is called before the
> > interrupts are tested.
> >
> > Signed-off-by: Lino Sanfilippo <l.sanfilippo@kunbus.com>
> > ---
> > drivers/char/tpm/tpm-chip.c | 38 +++++++++++++++++++++------------
> > drivers/char/tpm/tpm.h | 1 +
> > drivers/char/tpm/tpm_tis_core.c | 5 +++++
> > 3 files changed, 30 insertions(+), 14 deletions(-)
> >
> > diff --git a/drivers/char/tpm/tpm-chip.c b/drivers/char/tpm/tpm-chip.c
> > index 783d65fc71f0..370aa1f529f2 100644
> > --- a/drivers/char/tpm/tpm-chip.c
> > +++ b/drivers/char/tpm/tpm-chip.c
> > @@ -543,6 +543,30 @@ static int tpm_get_pcr_allocation(struct tpm_chip *chip)
> > return rc;
> > }
> >
> > +/*
> > + * tpm_chip_startup() - performs auto startup and allocates the PCRs
> > + * @chip: TPM chip to use.
> > + */
> > +int tpm_chip_startup(struct tpm_chip *chip)
> > +{
> > + int rc;
> > +
> > + rc = tpm_chip_start(chip);
> > + if (rc)
> > + return rc;
> > +
> > + rc = tpm_auto_startup(chip);
> > + if (rc)
> > + goto stop;
> > +
> > + rc = tpm_get_pcr_allocation(chip);
> > +stop:
> > + tpm_chip_stop(chip);
> > +
> > + return rc;
> > +}
> > +EXPORT_SYMBOL_GPL(tpm_chip_startup);
> > +
> > /*
> > * tpm_chip_register() - create a character device for the TPM chip
> > * @chip: TPM chip to use.
> > @@ -558,20 +582,6 @@ int tpm_chip_register(struct tpm_chip *chip)
> > {
> > int rc;
> >
> > - rc = tpm_chip_start(chip);
> > - if (rc)
> > - return rc;
> > - rc = tpm_auto_startup(chip);
> > - if (rc) {
> > - tpm_chip_stop(chip);
> > - return rc;
> > - }
> > -
> > - rc = tpm_get_pcr_allocation(chip);
> > - tpm_chip_stop(chip);
> > - if (rc)
> > - return rc;
> > -
> > tpm_sysfs_add_device(chip);
> >
> > tpm_bios_log_setup(chip);
> > diff --git a/drivers/char/tpm/tpm.h b/drivers/char/tpm/tpm.h
> > index 24ee4e1cc452..919bb0b88b12 100644
> > --- a/drivers/char/tpm/tpm.h
> > +++ b/drivers/char/tpm/tpm.h
> > @@ -190,6 +190,7 @@ static inline void tpm_msleep(unsigned int delay_msec)
> > delay_msec * 1000);
> > };
> >
> > +int tpm_chip_startup(struct tpm_chip *chip);
> > int tpm_chip_start(struct tpm_chip *chip);
> > void tpm_chip_stop(struct tpm_chip *chip);
> > struct tpm_chip *tpm_find_get_ops(struct tpm_chip *chip);
> > diff --git a/drivers/char/tpm/tpm_tis_core.c b/drivers/char/tpm/tpm_tis_core.c
> > index ddaf362e62c1..94a2bfb244b3 100644
> > --- a/drivers/char/tpm/tpm_tis_core.c
> > +++ b/drivers/char/tpm/tpm_tis_core.c
> > @@ -1129,6 +1129,11 @@ int tpm_tis_core_init(struct device *dev, struct tpm_tis_data *priv, int irq,
> > /* INTERRUPT Setup */
> > init_waitqueue_head(&priv->read_queue);
> > init_waitqueue_head(&priv->int_queue);
> > +
> > + rc = tpm_chip_startup(chip);
> > + if (rc)
> > + goto out_err;
> > +
> > if (irq != -1) {
> > /*
> > * Before doing irq testing issue a command to the TPM in polling mode
>
> Jarko, thanks for the review so far. What about this patch, are there any concerns from your side?

No concerns on this one.

BR, Jarkko