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

Lino Sanfilippo
2022-11-28T12:54:08Z

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?

Regards,
Lino