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SubjectRe: [PATCH 1/2 v4] tpm: cmd_ready command can be issued only after granting locality
On Sun, Feb 25, 2018 at 10:37:08AM +0000, Winkler, Tomas wrote:
> >
> > 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@intel.com>
> > > Tested-by: Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com>
> > > ---
> > > 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.
>
> No, it shouldn't. I cannot find any reference to this statement, I've already explained my reasoning in a previous mail.
>
> >
> > > +
> > > + 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.
>
> Yep, missed that, will resubmit
>
>
> > I can fix these cosmetic issues
> >
> > Reviewed-by: Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com>
> >
> > Doesn't this need
> >
> > Fixes: 877c57d0d0ca ("tpm_crb: request and relinquish locality 0")
> > And shouldn't this also have
> >
> > Cc: stable@vger.kernel.org
> >
> > ?
> Good points
> Thanks
> Tomas

Tomas, I updated v4 myself and pushed it to master/next. Please tell
me if there is anything wrong and I will fix it.

/Jarkko

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