On Mon, Jun 15, 2026 at 05:48:43AM +0100, Daniel Golle wrote:
> tpm_tis_core_init() releases locality 0 then immediately reclaims it via
> tpm_chip_start(); some TPMs (e.g. Nuvoton NPCT, TPM 2.0) need a few ms
> before granting it again, so probe fails with -1. This back-to-back
> release/request was added with the locality claim around TPM_INT_ENABLE.
>
> Wait for the chip to settle after releasing the locality. A delay of
> TPM_TIMEOUT (5 ms) in __tpm_tis_relinquish_locality() is reliable; values
> below 3 ms are not.
>
> Fixes: 0ef333f5ba7f ("tpm: add request_locality before write TPM_INT_ENABLE")
> Cc: [email protected]
> Signed-off-by: Daniel Golle <[email protected]>
> ---
> drivers/char/tpm/tpm_tis_core.c | 2 ++
> 1 file changed, 2 insertions(+)
>
> diff --git a/drivers/char/tpm/tpm_tis_core.c b/drivers/char/tpm/tpm_tis_core.c
> index 21d79ad3b164..6b90ff50c78d 100644
> --- a/drivers/char/tpm/tpm_tis_core.c
> +++ b/drivers/char/tpm/tpm_tis_core.c
> @@ -171,6 +171,8 @@ static int __tpm_tis_relinquish_locality(struct
> tpm_tis_data *priv, int l)
> {
> tpm_tis_write8(priv, TPM_ACCESS(l), TPM_ACCESS_ACTIVE_LOCALITY);
>
> + tpm_msleep(TPM_TIMEOUT);
> +
> return 0;
> }
>
> --
> 2.54.0
>
I think this is totally fine.
Reviewed-by: Jarkko Sakkinen <[email protected]>
BR, Jarkko
