| Message ID | 1487259216-28955-1-git-send-email-peter.huewe@infineon.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
On Thu, Feb 16, 2017 at 03:33:36PM +0000, Peter Huewe wrote: > From: Alexander Steffen <Alexander.Steffen@infineon.com> > > TIS v1.3 for TPM 1.2 and PTP for TPM 2.0 disagree about which timeout > value applies to reading a valid burstcount. It is TIMEOUT_D according to > TIS, but TIMEOUT_A according to PTP, so choose the appropriate value > depending on whether we deal with a TPM 1.2 or a TPM 2.0. > > This is important since according to the PTP TIMEOUT_D is much smaller > than TIMEOUT_A. So the previous implementation could run into timeouts > with a TPM 2.0, even though the TPM was behaving perfectly fine. > > During tpm2_probe TIMEOUT_D will be used even with a TPM 2.0, because > TPM_CHIP_FLAG_TPM2 is not yet set. This is fine, since the timeout values > will only be changed afterwards by tpm_get_timeouts. Until then > TIS_TIMEOUT_D_MAX applies, which is large enough. > > Cc: stable@vger.kernel.org > Fixes: aec04cbdf723 ("tpm: TPM 2.0 FIFO Interface") > > Signed-off-by: Alexander Steffen <Alexander.Steffen@infineon.com> > Signed-off-by: Peter Huewe <peter.huewe@infineon.com> Reviewed-by: Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com> /Jarkko > --- > drivers/char/tpm/tpm_tis_core.c | 6 ++++-- > 1 file changed, 4 insertions(+), 2 deletions(-) > > diff --git a/drivers/char/tpm/tpm_tis_core.c b/drivers/char/tpm/tpm_tis_core.c > index c0f296b5d413..fc0e9a2734ed 100644 > --- a/drivers/char/tpm/tpm_tis_core.c > +++ b/drivers/char/tpm/tpm_tis_core.c > @@ -160,8 +160,10 @@ static int get_burstcount(struct tpm_chip *chip) > u32 value; > > /* wait for burstcount */ > - /* which timeout value, spec has 2 answers (c & d) */ > - stop = jiffies + chip->timeout_d; > + if (chip->flags & TPM_CHIP_FLAG_TPM2) > + stop = jiffies + chip->timeout_a; > + else > + stop = jiffies + chip->timeout_d; > do { > rc = tpm_tis_read32(priv, TPM_STS(priv->locality), &value); > if (rc < 0) > -- > 2.7.4 > ------------------------------------------------------------------------------ Check out the vibrant tech community on one of the world's most engaging tech sites, SlashDot.org! http://sdm.link/slashdot
On Thu, Feb 16, 2017 at 03:33:36PM +0000, Peter Huewe wrote: > From: Alexander Steffen <Alexander.Steffen@infineon.com> > > TIS v1.3 for TPM 1.2 and PTP for TPM 2.0 disagree about which timeout > value applies to reading a valid burstcount. It is TIMEOUT_D according to > TIS, but TIMEOUT_A according to PTP, so choose the appropriate value > depending on whether we deal with a TPM 1.2 or a TPM 2.0. > > This is important since according to the PTP TIMEOUT_D is much smaller > than TIMEOUT_A. So the previous implementation could run into timeouts > with a TPM 2.0, even though the TPM was behaving perfectly fine. > > During tpm2_probe TIMEOUT_D will be used even with a TPM 2.0, because > TPM_CHIP_FLAG_TPM2 is not yet set. This is fine, since the timeout values > will only be changed afterwards by tpm_get_timeouts. Until then > TIS_TIMEOUT_D_MAX applies, which is large enough. > > Cc: stable@vger.kernel.org > Fixes: aec04cbdf723 ("tpm: TPM 2.0 FIFO Interface") > > Signed-off-by: Alexander Steffen <Alexander.Steffen@infineon.com> > Signed-off-by: Peter Huewe <peter.huewe@infineon.com> Pushed. /Jarkko > --- > drivers/char/tpm/tpm_tis_core.c | 6 ++++-- > 1 file changed, 4 insertions(+), 2 deletions(-) > > diff --git a/drivers/char/tpm/tpm_tis_core.c b/drivers/char/tpm/tpm_tis_core.c > index c0f296b5d413..fc0e9a2734ed 100644 > --- a/drivers/char/tpm/tpm_tis_core.c > +++ b/drivers/char/tpm/tpm_tis_core.c > @@ -160,8 +160,10 @@ static int get_burstcount(struct tpm_chip *chip) > u32 value; > > /* wait for burstcount */ > - /* which timeout value, spec has 2 answers (c & d) */ > - stop = jiffies + chip->timeout_d; > + if (chip->flags & TPM_CHIP_FLAG_TPM2) > + stop = jiffies + chip->timeout_a; > + else > + stop = jiffies + chip->timeout_d; > do { > rc = tpm_tis_read32(priv, TPM_STS(priv->locality), &value); > if (rc < 0) > -- > 2.7.4 > ------------------------------------------------------------------------------ Check out the vibrant tech community on one of the world's most engaging tech sites, SlashDot.org! http://sdm.link/slashdot
diff --git a/drivers/char/tpm/tpm_tis_core.c b/drivers/char/tpm/tpm_tis_core.c index c0f296b5d413..fc0e9a2734ed 100644 --- a/drivers/char/tpm/tpm_tis_core.c +++ b/drivers/char/tpm/tpm_tis_core.c @@ -160,8 +160,10 @@ static int get_burstcount(struct tpm_chip *chip) u32 value; /* wait for burstcount */ - /* which timeout value, spec has 2 answers (c & d) */ - stop = jiffies + chip->timeout_d; + if (chip->flags & TPM_CHIP_FLAG_TPM2) + stop = jiffies + chip->timeout_a; + else + stop = jiffies + chip->timeout_d; do { rc = tpm_tis_read32(priv, TPM_STS(priv->locality), &value); if (rc < 0)