Re: [PATCH] tpm_tis: use default timeout value if chip reports it as zero

Jarkko Sakkinen
2017-01-16T09:42:11Z

On Fri, Jan 13, 2017 at 10:37:00PM +0100, Maciej S. Szmigiero wrote:
> Since commit 1107d065fdf1 ("tpm_tis: Introduce intermediate layer for TPM
> access") Atmel 3203 TPM on ThinkPad X61S (TPM firmware version 13.9) no
> longer works.
> The initialization proceeds fine until we get and start using chip-reported
> timeouts - and the chip reports C and D timeouts of zero.
>
> It turns out that until commit 8e54caf407b98e ("tpm: Provide a generic
> means to override the chip returned timeouts") we had actually let default
> timeout values remain in this case, so let's bring back this behavior to
> make chips like Atmel 3203 work again.
>
> Use a common code that was introduced by that commit so a warning is
> printed in this case and /sys/class/tpm/tpm*/timeouts correctly says the
> timeouts aren't chip-original.
>
> Signed-off-by: Maciej S. Szmigiero <mail@maciej.szmigiero.name>
>
> Fixes: 1107d065fdf1 ("tpm_tis: Introduce intermediate layer for TPM access")
> Cc: stable@vger.kernel.org

Reviewed-by: Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com>

/Jarkko

> ---
> This replaces "tpm_tis: override reported C and D timeouts for Atmel 3203"
> submission.
>
> drivers/char/tpm/tpm-interface.c | 53 ++++++++++++++++++++++++----------------
> 1 file changed, 32 insertions(+), 21 deletions(-)
>
> diff --git a/drivers/char/tpm/tpm-interface.c b/drivers/char/tpm/tpm-interface.c
> index fecdd3fa8126..a3461cbdde5f 100644
> --- a/drivers/char/tpm/tpm-interface.c
> +++ b/drivers/char/tpm/tpm-interface.c
> @@ -522,8 +522,7 @@ static int tpm_startup(struct tpm_chip *chip, __be16 startup_type)
> int tpm_get_timeouts(struct tpm_chip *chip)
> {
> cap_t cap;
> - unsigned long new_timeout[4];
> - unsigned long old_timeout[4];
> + unsigned long timeout_old[4], timeout_chip[4], timeout_eff[4];
> ssize_t rc;
>
> if (chip->flags & TPM_CHIP_FLAG_HAVE_TIMEOUTS)
> @@ -564,11 +563,15 @@ int tpm_get_timeouts(struct tpm_chip *chip)
> return rc;
> }
>
> - old_timeout[0] = be32_to_cpu(cap.timeout.a);
> - old_timeout[1] = be32_to_cpu(cap.timeout.b);
> - old_timeout[2] = be32_to_cpu(cap.timeout.c);
> - old_timeout[3] = be32_to_cpu(cap.timeout.d);
> - memcpy(new_timeout, old_timeout, sizeof(new_timeout));
> + timeout_old[0] = jiffies_to_usecs(chip->timeout_a);
> + timeout_old[1] = jiffies_to_usecs(chip->timeout_b);
> + timeout_old[2] = jiffies_to_usecs(chip->timeout_c);
> + timeout_old[3] = jiffies_to_usecs(chip->timeout_d);
> + timeout_chip[0] = be32_to_cpu(cap.timeout.a);
> + timeout_chip[1] = be32_to_cpu(cap.timeout.b);
> + timeout_chip[2] = be32_to_cpu(cap.timeout.c);
> + timeout_chip[3] = be32_to_cpu(cap.timeout.d);
> + memcpy(timeout_eff, timeout_chip, sizeof(timeout_eff));
>
> /*
> * Provide ability for vendor overrides of timeout values in case
> @@ -576,16 +579,24 @@ int tpm_get_timeouts(struct tpm_chip *chip)
> */
> if (chip->ops->update_timeouts != NULL)
> chip->timeout_adjusted =
> - chip->ops->update_timeouts(chip, new_timeout);
> + chip->ops->update_timeouts(chip, timeout_eff);
>
> if (!chip->timeout_adjusted) {
> - /* Don't overwrite default if value is 0 */
> - if (new_timeout[0] != 0 && new_timeout[0] < 1000) {
> - int i;
> + /* Restore default if chip reported 0 */
> + int i;
>
> + for (i = 0; i < ARRAY_SIZE(timeout_eff); i++) {
> + if (timeout_eff[i])
> + continue;
> +
> + timeout_eff[i] = timeout_old[i];
> + chip->timeout_adjusted = true;
> + }
> +
> + if (timeout_eff[0] != 0 && timeout_eff[0] < 1000) {
> /* timeouts in msec rather usec */
> - for (i = 0; i != ARRAY_SIZE(new_timeout); i++)
> - new_timeout[i] *= 1000;
> + for (i = 0; i != ARRAY_SIZE(timeout_eff); i++)
> + timeout_eff[i] *= 1000;
> chip->timeout_adjusted = true;
> }
> }
> @@ -594,16 +605,16 @@ int tpm_get_timeouts(struct tpm_chip *chip)
> if (chip->timeout_adjusted) {
> dev_info(&chip->dev,
> HW_ERR "Adjusting reported timeouts: A %lu->%luus B %lu->%luus C %lu->%luus D %lu->%luus\n",
> - old_timeout[0], new_timeout[0],
> - old_timeout[1], new_timeout[1],
> - old_timeout[2], new_timeout[2],
> - old_timeout[3], new_timeout[3]);
> + timeout_chip[0], timeout_eff[0],
> + timeout_chip[1], timeout_eff[1],
> + timeout_chip[2], timeout_eff[2],
> + timeout_chip[3], timeout_eff[3]);
> }
>
> - chip->timeout_a = usecs_to_jiffies(new_timeout[0]);
> - chip->timeout_b = usecs_to_jiffies(new_timeout[1]);
> - chip->timeout_c = usecs_to_jiffies(new_timeout[2]);
> - chip->timeout_d = usecs_to_jiffies(new_timeout[3]);
> + chip->timeout_a = usecs_to_jiffies(timeout_eff[0]);
> + chip->timeout_b = usecs_to_jiffies(timeout_eff[1]);
> + chip->timeout_c = usecs_to_jiffies(timeout_eff[2]);
> + chip->timeout_d = usecs_to_jiffies(timeout_eff[3]);
>
> rc = tpm_getcap(chip, TPM_CAP_PROP_TIS_DURATION, &cap,
> "attempting to determine the durations");
>