On Sat, Feb 24, 2018 at 05:43:16PM +0200, Tomas Winkler wrote:
> The correct sequence is to first request locality and only after
> that perform cmd_ready handshake, otherwise the hardware will drop
> the subsequent message as from the device point of view the cmd_ready
> handshake wasn't performed. Symmetrically locality has to be relinquished
> only after going idle handshake has completed, this requires that
> go_idle has to poll for the completion and as well locality
> relinquish has to poll for completion so it is not overridden
> in back to back commands flow.
>
> The issue is only visible on devices that support multiple localities.
>
> Signed-off-by: Tomas Winkler <tomas.winkler@xxxxxxxxx>
> Tested-by: Jarkko Sakkinen <jarkko.sakkinen@xxxxxxxxxxxxxxx>
> ---
> V2: poll for locality relinquish completion
> V3: 1. Print error message upon locality relinquish failure
> 2. Don't override rc code on error path with locality relinquish
> V4: 3. Don't capture locality relinquish error code in rc, just print
> the error message.
>
> return value.
> drivers/char/tpm/tpm-interface.c | 20 +++++---
> drivers/char/tpm/tpm_crb.c | 108 +++++++++++++++++++++++++++------------
> drivers/char/tpm/tpm_tis_core.c | 4 +-
> include/linux/tpm.h | 2 +-
> 4 files changed, 93 insertions(+), 41 deletions(-)
>
> diff --git a/drivers/char/tpm/tpm-interface.c b/drivers/char/tpm/tpm-interface.c
> index 9e80a953d693..4d74bacca5a1 100644
> --- a/drivers/char/tpm/tpm-interface.c
> +++ b/drivers/char/tpm/tpm-interface.c
> @@ -422,8 +422,6 @@ ssize_t tpm_transmit(struct tpm_chip *chip, struct tpm_space *space,
> if (!(flags & TPM_TRANSMIT_UNLOCKED))
> mutex_lock(&chip->tpm_mutex);
>
> - if (chip->dev.parent)
> - pm_runtime_get_sync(chip->dev.parent);
>
> if (chip->ops->clk_enable != NULL)
> chip->ops->clk_enable(chip, true);
> @@ -439,6 +437,9 @@ ssize_t tpm_transmit(struct tpm_chip *chip, struct tpm_space *space,
> chip->locality = rc;
> }
>
> + if (chip->dev.parent)
> + pm_runtime_get_sync(chip->dev.parent);
> +
> rc = tpm2_prepare_space(chip, space, ordinal, buf);
> if (rc)
> goto out;
> @@ -499,17 +500,24 @@ ssize_t tpm_transmit(struct tpm_chip *chip, struct tpm_space *space,
> rc = tpm2_commit_space(chip, space, ordinal, buf, &len);
>
> out:
> + if (chip->dev.parent)
> + pm_runtime_put_sync(chip->dev.parent);
> +
> if (need_locality && chip->ops->relinquish_locality) {
> - chip->ops->relinquish_locality(chip, chip->locality);
> + /* this coud be on error path, don't override error code */
> + int l_rc = chip->ops->relinquish_locality(chip, chip->locality);
Declaration should be in the beginning of the function.
> +
> + if (l_rc) {
> + dev_err(&chip->dev, "%s: relinquish_locality: error %d\n",
> + __func__, l_rc);
> + }
In kernel coding style, this should be w/o curly braces.
I can fix these cosmetic issues
Reviewed-by: Jarkko Sakkinen <jarkko.sakkinen@xxxxxxxxxxxxxxx>
Doesn't this need
Fixes: 877c57d0d0ca ("tpm_crb: request and relinquish locality 0")
And shouldn't this also have
Cc: stable@xxxxxxxxxxxxxxx
?
/Jarkko
