Message ID | 20170328152938.14539-1-enric.balletbo@collabora.com |
---|---|
State | New |
Headers | show |
On Tue, Mar 28, 2017 at 05:29:38PM +0200, Enric Balletbo i Serra wrote: > From: Bryan Freed <bfreed@chromium.org> > > When the I2C Infineon part is attached to an I2C adapter that imposes > a size limitation, large requests will fail with -EOPNOTSUPP. Retry > them with a sane minimum size without re-issuing the 0x05 command > as this appears to occasionally put the TPM in a bad state. > > Signed-off-by: Bryan Freed <bfreed@chromium.org> > [rework the patch to adapt to the feedback received] > Signed-off-by: Enric Balletbo i Serra <enric.balletbo@collabora.com> This looks O.K. now. Thanks for remembering the adaptor limit. Acked-by: Andrew Lunn <andrew@lunn.ch> Andrew ------------------------------------------------------------------------------ Check out the vibrant tech community on one of the world's most engaging tech sites, Slashdot.org! http://sdm.link/slashdot
On Tue, Mar 28, 2017 at 05:29:38PM +0200, Enric Balletbo i Serra wrote: > From: Bryan Freed <bfreed@chromium.org> > > When the I2C Infineon part is attached to an I2C adapter that imposes > a size limitation, large requests will fail with -EOPNOTSUPP. Retry > them with a sane minimum size without re-issuing the 0x05 command > as this appears to occasionally put the TPM in a bad state. > > Signed-off-by: Bryan Freed <bfreed@chromium.org> > [rework the patch to adapt to the feedback received] > Signed-off-by: Enric Balletbo i Serra <enric.balletbo@collabora.com> > --- > This is a reworked version of the original patch based on the > suggestion made by Wolfram Sang to simply fall back to a sane minimum > when the maximum fails. > > Changes since v2: > - Do not remove faster transfers when chip is SLB9645 (Peter Huewe) > - Remember the adapterlimit length once it fails to not generate extra > i2c core messages (suggested by Andrew Lunn) > Changes since v1: > - Check the correct return value (-EOPNOTSUPP instead of -EINVAL) > - Fall back len to I2C_SMBUS_BLOCK_MAX if fails. > > drivers/char/tpm/tpm_i2c_infineon.c | 76 +++++++++++++++++++++++++++---------- > 1 file changed, 56 insertions(+), 20 deletions(-) Looking into this after taking of the request for 4.12. /Jarkko > > diff --git a/drivers/char/tpm/tpm_i2c_infineon.c b/drivers/char/tpm/tpm_i2c_infineon.c > index 62ee44e..fdefcdb 100644 > --- a/drivers/char/tpm/tpm_i2c_infineon.c > +++ b/drivers/char/tpm/tpm_i2c_infineon.c > @@ -70,6 +70,7 @@ struct tpm_inf_dev { > u8 buf[TPM_BUFSIZE + sizeof(u8)]; /* max. buffer size + addr */ > struct tpm_chip *chip; > enum i2c_chip_type chip_type; > + unsigned int adapterlimit; > }; > > static struct tpm_inf_dev tpm_dev; > @@ -111,6 +112,7 @@ static int iic_tpm_read(u8 addr, u8 *buffer, size_t len) > > int rc = 0; > int count; > + unsigned int msglen = len; > > /* Lock the adapter for the duration of the whole sequence. */ > if (!tpm_dev.client->adapter->algo->master_xfer) > @@ -131,27 +133,61 @@ static int iic_tpm_read(u8 addr, u8 *buffer, size_t len) > usleep_range(SLEEP_DURATION_LOW, SLEEP_DURATION_HI); > } > } else { > - /* slb9635 protocol should work in all cases */ > - for (count = 0; count < MAX_COUNT; count++) { > - rc = __i2c_transfer(tpm_dev.client->adapter, &msg1, 1); > - if (rc > 0) > - break; /* break here to skip sleep */ > - > - usleep_range(SLEEP_DURATION_LOW, SLEEP_DURATION_HI); > - } > - > - if (rc <= 0) > - goto out; > - > - /* After the TPM has successfully received the register address > - * it needs some time, thus we're sleeping here again, before > - * retrieving the data > + /* Expect to send one command message and one data message, but > + * support looping over each or both if necessary. > */ > - for (count = 0; count < MAX_COUNT; count++) { > - usleep_range(SLEEP_DURATION_LOW, SLEEP_DURATION_HI); > - rc = __i2c_transfer(tpm_dev.client->adapter, &msg2, 1); > - if (rc > 0) > - break; > + while (len > 0) { > + /* slb9635 protocol should work in all cases */ > + for (count = 0; count < MAX_COUNT; count++) { > + rc = __i2c_transfer(tpm_dev.client->adapter, > + &msg1, 1); > + if (rc > 0) > + break; /* break here to skip sleep */ > + > + usleep_range(SLEEP_DURATION_LOW, > + SLEEP_DURATION_HI); > + } > + > + if (rc <= 0) > + goto out; > + > + /* After the TPM has successfully received the register > + * address it needs some time, thus we're sleeping here > + * again, before retrieving the data > + */ > + for (count = 0; count < MAX_COUNT; count++) { > + if (tpm_dev.adapterlimit) { > + msglen = min_t(unsigned int, > + tpm_dev.adapterlimit, > + len); > + msg2.len = msglen; > + } > + usleep_range(SLEEP_DURATION_LOW, > + SLEEP_DURATION_HI); > + rc = __i2c_transfer(tpm_dev.client->adapter, > + &msg2, 1); > + if (rc > 0) { > + /* Since len is unsigned, make doubly > + * sure we do not underflow it. > + */ > + if (msglen > len) > + len = 0; > + else > + len -= msglen; > + msg2.buf += msglen; > + break; > + } > + /* If the I2C adapter rejected the request (e.g > + * when the quirk read_max_len < len) fall back > + * to a sane minimum value and try again. > + */ > + if (rc == -EOPNOTSUPP) > + tpm_dev.adapterlimit = > + I2C_SMBUS_BLOCK_MAX; > + } > + > + if (rc <= 0) > + goto out; > } > } > > -- > 2.9.3 > ------------------------------------------------------------------------------ Check out the vibrant tech community on one of the world's most engaging tech sites, Slashdot.org! http://sdm.link/slashdot
On Tue, Mar 28, 2017 at 05:29:38PM +0200, Enric Balletbo i Serra wrote: > From: Bryan Freed <bfreed@chromium.org> > > When the I2C Infineon part is attached to an I2C adapter that imposes > a size limitation, large requests will fail with -EOPNOTSUPP. Retry > them with a sane minimum size without re-issuing the 0x05 command > as this appears to occasionally put the TPM in a bad state. > > Signed-off-by: Bryan Freed <bfreed@chromium.org> > [rework the patch to adapt to the feedback received] > Signed-off-by: Enric Balletbo i Serra <enric.balletbo@collabora.com> > --- > This is a reworked version of the original patch based on the > suggestion made by Wolfram Sang to simply fall back to a sane minimum > when the maximum fails. > > Changes since v2: > - Do not remove faster transfers when chip is SLB9645 (Peter Huewe) > - Remember the adapterlimit length once it fails to not generate extra > i2c core messages (suggested by Andrew Lunn) > Changes since v1: > - Check the correct return value (-EOPNOTSUPP instead of -EINVAL) > - Fall back len to I2C_SMBUS_BLOCK_MAX if fails. > > drivers/char/tpm/tpm_i2c_infineon.c | 76 +++++++++++++++++++++++++++---------- > 1 file changed, 56 insertions(+), 20 deletions(-) > > diff --git a/drivers/char/tpm/tpm_i2c_infineon.c b/drivers/char/tpm/tpm_i2c_infineon.c > index 62ee44e..fdefcdb 100644 > --- a/drivers/char/tpm/tpm_i2c_infineon.c > +++ b/drivers/char/tpm/tpm_i2c_infineon.c > @@ -70,6 +70,7 @@ struct tpm_inf_dev { > u8 buf[TPM_BUFSIZE + sizeof(u8)]; /* max. buffer size + addr */ > struct tpm_chip *chip; > enum i2c_chip_type chip_type; > + unsigned int adapterlimit; > }; > > static struct tpm_inf_dev tpm_dev; > @@ -111,6 +112,7 @@ static int iic_tpm_read(u8 addr, u8 *buffer, size_t len) > > int rc = 0; > int count; > + unsigned int msglen = len; > > /* Lock the adapter for the duration of the whole sequence. */ > if (!tpm_dev.client->adapter->algo->master_xfer) > @@ -131,27 +133,61 @@ static int iic_tpm_read(u8 addr, u8 *buffer, size_t len) > usleep_range(SLEEP_DURATION_LOW, SLEEP_DURATION_HI); > } > } else { > - /* slb9635 protocol should work in all cases */ > - for (count = 0; count < MAX_COUNT; count++) { > - rc = __i2c_transfer(tpm_dev.client->adapter, &msg1, 1); > - if (rc > 0) > - break; /* break here to skip sleep */ > - > - usleep_range(SLEEP_DURATION_LOW, SLEEP_DURATION_HI); > - } > - > - if (rc <= 0) > - goto out; > - > - /* After the TPM has successfully received the register address > - * it needs some time, thus we're sleeping here again, before > - * retrieving the data > + /* Expect to send one command message and one data message, but > + * support looping over each or both if necessary. > */ > - for (count = 0; count < MAX_COUNT; count++) { > - usleep_range(SLEEP_DURATION_LOW, SLEEP_DURATION_HI); > - rc = __i2c_transfer(tpm_dev.client->adapter, &msg2, 1); > - if (rc > 0) > - break; > + while (len > 0) { > + /* slb9635 protocol should work in all cases */ > + for (count = 0; count < MAX_COUNT; count++) { > + rc = __i2c_transfer(tpm_dev.client->adapter, > + &msg1, 1); > + if (rc > 0) > + break; /* break here to skip sleep */ > + > + usleep_range(SLEEP_DURATION_LOW, > + SLEEP_DURATION_HI); > + } > + > + if (rc <= 0) > + goto out; > + > + /* After the TPM has successfully received the register > + * address it needs some time, thus we're sleeping here > + * again, before retrieving the data > + */ > + for (count = 0; count < MAX_COUNT; count++) { > + if (tpm_dev.adapterlimit) { > + msglen = min_t(unsigned int, > + tpm_dev.adapterlimit, > + len); > + msg2.len = msglen; > + } > + usleep_range(SLEEP_DURATION_LOW, > + SLEEP_DURATION_HI); > + rc = __i2c_transfer(tpm_dev.client->adapter, > + &msg2, 1); > + if (rc > 0) { > + /* Since len is unsigned, make doubly > + * sure we do not underflow it. > + */ > + if (msglen > len) > + len = 0; > + else > + len -= msglen; > + msg2.buf += msglen; > + break; > + } > + /* If the I2C adapter rejected the request (e.g > + * when the quirk read_max_len < len) fall back > + * to a sane minimum value and try again. > + */ > + if (rc == -EOPNOTSUPP) > + tpm_dev.adapterlimit = > + I2C_SMBUS_BLOCK_MAX; > + } > + > + if (rc <= 0) > + goto out; > } > } > > -- > 2.9.3 > Reviewed-by: Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com> Peter, Andrew, anyone: Tested-by? /Jarkko ------------------------------------------------------------------------------ Check out the vibrant tech community on one of the world's most engaging tech sites, Slashdot.org! http://sdm.link/slashdot
Am 5. April 2017 11:03:27 MESZ schrieb Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com>: >On Tue, Mar 28, 2017 at 05:29:38PM +0200, Enric Balletbo i Serra wrote: >> From: Bryan Freed <bfreed@chromium.org> >> >> When the I2C Infineon part is attached to an I2C adapter that imposes >> a size limitation, large requests will fail with -EOPNOTSUPP. Retry >> them with a sane minimum size without re-issuing the 0x05 command >> as this appears to occasionally put the TPM in a bad state. >> >> Signed-off-by: Bryan Freed <bfreed@chromium.org> >> [rework the patch to adapt to the feedback received] >> Signed-off-by: Enric Balletbo i Serra <enric.balletbo@collabora.com> >> --- >> This is a reworked version of the original patch based on the >> suggestion made by Wolfram Sang to simply fall back to a sane minimum >> when the maximum fails. >> >> Changes since v2: >> - Do not remove faster transfers when chip is SLB9645 (Peter Huewe) >> - Remember the adapterlimit length once it fails to not generate >extra >> i2c core messages (suggested by Andrew Lunn) >> Changes since v1: >> - Check the correct return value (-EOPNOTSUPP instead of -EINVAL) >> - Fall back len to I2C_SMBUS_BLOCK_MAX if fails. >> >> drivers/char/tpm/tpm_i2c_infineon.c | 76 >+++++++++++++++++++++++++++---------- >> 1 file changed, 56 insertions(+), 20 deletions(-) >> >> diff --git a/drivers/char/tpm/tpm_i2c_infineon.c >b/drivers/char/tpm/tpm_i2c_infineon.c >> index 62ee44e..fdefcdb 100644 >> --- a/drivers/char/tpm/tpm_i2c_infineon.c >> +++ b/drivers/char/tpm/tpm_i2c_infineon.c >> @@ -70,6 +70,7 @@ struct tpm_inf_dev { >> u8 buf[TPM_BUFSIZE + sizeof(u8)]; /* max. buffer size + addr */ >> struct tpm_chip *chip; >> enum i2c_chip_type chip_type; >> + unsigned int adapterlimit; >> }; >> >> static struct tpm_inf_dev tpm_dev; >> @@ -111,6 +112,7 @@ static int iic_tpm_read(u8 addr, u8 *buffer, >size_t len) >> >> int rc = 0; >> int count; >> + unsigned int msglen = len; >> >> /* Lock the adapter for the duration of the whole sequence. */ >> if (!tpm_dev.client->adapter->algo->master_xfer) >> @@ -131,27 +133,61 @@ static int iic_tpm_read(u8 addr, u8 *buffer, >size_t len) >> usleep_range(SLEEP_DURATION_LOW, SLEEP_DURATION_HI); >> } >> } else { >> - /* slb9635 protocol should work in all cases */ >> - for (count = 0; count < MAX_COUNT; count++) { >> - rc = __i2c_transfer(tpm_dev.client->adapter, &msg1, 1); >> - if (rc > 0) >> - break; /* break here to skip sleep */ >> - >> - usleep_range(SLEEP_DURATION_LOW, SLEEP_DURATION_HI); >> - } >> - >> - if (rc <= 0) >> - goto out; >> - >> - /* After the TPM has successfully received the register address >> - * it needs some time, thus we're sleeping here again, before >> - * retrieving the data >> + /* Expect to send one command message and one data message, but >> + * support looping over each or both if necessary. >> */ >> - for (count = 0; count < MAX_COUNT; count++) { >> - usleep_range(SLEEP_DURATION_LOW, SLEEP_DURATION_HI); >> - rc = __i2c_transfer(tpm_dev.client->adapter, &msg2, 1); >> - if (rc > 0) >> - break; >> + while (len > 0) { >> + /* slb9635 protocol should work in all cases */ >> + for (count = 0; count < MAX_COUNT; count++) { >> + rc = __i2c_transfer(tpm_dev.client->adapter, >> + &msg1, 1); >> + if (rc > 0) >> + break; /* break here to skip sleep */ >> + >> + usleep_range(SLEEP_DURATION_LOW, >> + SLEEP_DURATION_HI); >> + } >> + >> + if (rc <= 0) >> + goto out; >> + >> + /* After the TPM has successfully received the register >> + * address it needs some time, thus we're sleeping here >> + * again, before retrieving the data >> + */ >> + for (count = 0; count < MAX_COUNT; count++) { >> + if (tpm_dev.adapterlimit) { >> + msglen = min_t(unsigned int, >> + tpm_dev.adapterlimit, >> + len); >> + msg2.len = msglen; >> + } >> + usleep_range(SLEEP_DURATION_LOW, >> + SLEEP_DURATION_HI); >> + rc = __i2c_transfer(tpm_dev.client->adapter, >> + &msg2, 1); >> + if (rc > 0) { >> + /* Since len is unsigned, make doubly >> + * sure we do not underflow it. >> + */ >> + if (msglen > len) >> + len = 0; >> + else >> + len -= msglen; >> + msg2.buf += msglen; >> + break; >> + } >> + /* If the I2C adapter rejected the request (e.g >> + * when the quirk read_max_len < len) fall back >> + * to a sane minimum value and try again. >> + */ >> + if (rc == -EOPNOTSUPP) >> + tpm_dev.adapterlimit = >> + I2C_SMBUS_BLOCK_MAX; >> + } >> + >> + if (rc <= 0) >> + goto out; >> } >> } >> >> -- >> 2.9.3 >> > >Reviewed-by: Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com> > >Peter, Andrew, anyone: Tested-by? > Not yet, I'll put it on my list to test. Hopefully by next tuesday. Peter >/Jarkko
> Reviewed-by: Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com> > > Peter, Andrew, anyone: Tested-by? Sorry, i don't have the hardware. All i can give you is: Reviewed-by: Andrew Lunn <andrew@lunn.ch> Andrew ------------------------------------------------------------------------------ Check out the vibrant tech community on one of the world's most engaging tech sites, Slashdot.org! http://sdm.link/slashdot
On Wed, Apr 05, 2017 at 03:24:31PM +0200, Andrew Lunn wrote: > > Reviewed-by: Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com> > > > > Peter, Andrew, anyone: Tested-by? > > Sorry, i don't have the hardware. All i can give you is: > > Reviewed-by: Andrew Lunn <andrew@lunn.ch> > > Andrew Thank you. /Jarkko ------------------------------------------------------------------------------ Check out the vibrant tech community on one of the world's most engaging tech sites, Slashdot.org! http://sdm.link/slashdot
On Wed, Apr 05, 2017 at 12:05:32PM +0200, Peter Huewe wrote: > > > Am 5. April 2017 11:03:27 MESZ schrieb Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com>: > >On Tue, Mar 28, 2017 at 05:29:38PM +0200, Enric Balletbo i Serra wrote: > >> From: Bryan Freed <bfreed@chromium.org> > >> > >> When the I2C Infineon part is attached to an I2C adapter that imposes > >> a size limitation, large requests will fail with -EOPNOTSUPP. Retry > >> them with a sane minimum size without re-issuing the 0x05 command > >> as this appears to occasionally put the TPM in a bad state. > >> > >> Signed-off-by: Bryan Freed <bfreed@chromium.org> > >> [rework the patch to adapt to the feedback received] > >> Signed-off-by: Enric Balletbo i Serra <enric.balletbo@collabora.com> > >> --- > >> This is a reworked version of the original patch based on the > >> suggestion made by Wolfram Sang to simply fall back to a sane minimum > >> when the maximum fails. > >> > >> Changes since v2: > >> - Do not remove faster transfers when chip is SLB9645 (Peter Huewe) > >> - Remember the adapterlimit length once it fails to not generate > >extra > >> i2c core messages (suggested by Andrew Lunn) > >> Changes since v1: > >> - Check the correct return value (-EOPNOTSUPP instead of -EINVAL) > >> - Fall back len to I2C_SMBUS_BLOCK_MAX if fails. > >> > >> drivers/char/tpm/tpm_i2c_infineon.c | 76 > >+++++++++++++++++++++++++++---------- > >> 1 file changed, 56 insertions(+), 20 deletions(-) > >> > >> diff --git a/drivers/char/tpm/tpm_i2c_infineon.c > >b/drivers/char/tpm/tpm_i2c_infineon.c > >> index 62ee44e..fdefcdb 100644 > >> --- a/drivers/char/tpm/tpm_i2c_infineon.c > >> +++ b/drivers/char/tpm/tpm_i2c_infineon.c > >> @@ -70,6 +70,7 @@ struct tpm_inf_dev { > >> u8 buf[TPM_BUFSIZE + sizeof(u8)]; /* max. buffer size + addr */ > >> struct tpm_chip *chip; > >> enum i2c_chip_type chip_type; > >> + unsigned int adapterlimit; > >> }; > >> > >> static struct tpm_inf_dev tpm_dev; > >> @@ -111,6 +112,7 @@ static int iic_tpm_read(u8 addr, u8 *buffer, > >size_t len) > >> > >> int rc = 0; > >> int count; > >> + unsigned int msglen = len; > >> > >> /* Lock the adapter for the duration of the whole sequence. */ > >> if (!tpm_dev.client->adapter->algo->master_xfer) > >> @@ -131,27 +133,61 @@ static int iic_tpm_read(u8 addr, u8 *buffer, > >size_t len) > >> usleep_range(SLEEP_DURATION_LOW, SLEEP_DURATION_HI); > >> } > >> } else { > >> - /* slb9635 protocol should work in all cases */ > >> - for (count = 0; count < MAX_COUNT; count++) { > >> - rc = __i2c_transfer(tpm_dev.client->adapter, &msg1, 1); > >> - if (rc > 0) > >> - break; /* break here to skip sleep */ > >> - > >> - usleep_range(SLEEP_DURATION_LOW, SLEEP_DURATION_HI); > >> - } > >> - > >> - if (rc <= 0) > >> - goto out; > >> - > >> - /* After the TPM has successfully received the register address > >> - * it needs some time, thus we're sleeping here again, before > >> - * retrieving the data > >> + /* Expect to send one command message and one data message, but > >> + * support looping over each or both if necessary. > >> */ > >> - for (count = 0; count < MAX_COUNT; count++) { > >> - usleep_range(SLEEP_DURATION_LOW, SLEEP_DURATION_HI); > >> - rc = __i2c_transfer(tpm_dev.client->adapter, &msg2, 1); > >> - if (rc > 0) > >> - break; > >> + while (len > 0) { > >> + /* slb9635 protocol should work in all cases */ > >> + for (count = 0; count < MAX_COUNT; count++) { > >> + rc = __i2c_transfer(tpm_dev.client->adapter, > >> + &msg1, 1); > >> + if (rc > 0) > >> + break; /* break here to skip sleep */ > >> + > >> + usleep_range(SLEEP_DURATION_LOW, > >> + SLEEP_DURATION_HI); > >> + } > >> + > >> + if (rc <= 0) > >> + goto out; > >> + > >> + /* After the TPM has successfully received the register > >> + * address it needs some time, thus we're sleeping here > >> + * again, before retrieving the data > >> + */ > >> + for (count = 0; count < MAX_COUNT; count++) { > >> + if (tpm_dev.adapterlimit) { > >> + msglen = min_t(unsigned int, > >> + tpm_dev.adapterlimit, > >> + len); > >> + msg2.len = msglen; > >> + } > >> + usleep_range(SLEEP_DURATION_LOW, > >> + SLEEP_DURATION_HI); > >> + rc = __i2c_transfer(tpm_dev.client->adapter, > >> + &msg2, 1); > >> + if (rc > 0) { > >> + /* Since len is unsigned, make doubly > >> + * sure we do not underflow it. > >> + */ > >> + if (msglen > len) > >> + len = 0; > >> + else > >> + len -= msglen; > >> + msg2.buf += msglen; > >> + break; > >> + } > >> + /* If the I2C adapter rejected the request (e.g > >> + * when the quirk read_max_len < len) fall back > >> + * to a sane minimum value and try again. > >> + */ > >> + if (rc == -EOPNOTSUPP) > >> + tpm_dev.adapterlimit = > >> + I2C_SMBUS_BLOCK_MAX; > >> + } > >> + > >> + if (rc <= 0) > >> + goto out; > >> } > >> } > >> > >> -- > >> 2.9.3 > >> > > > >Reviewed-by: Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com> > > > >Peter, Andrew, anyone: Tested-by? > > > > Not yet, I'll put it on my list to test. > Hopefully by next tuesday. > Peter Ok, thanks. I can push this to my master branch if that would help to ease the testig? /Jarkko ------------------------------------------------------------------------------ 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_i2c_infineon.c b/drivers/char/tpm/tpm_i2c_infineon.c index 62ee44e..fdefcdb 100644 --- a/drivers/char/tpm/tpm_i2c_infineon.c +++ b/drivers/char/tpm/tpm_i2c_infineon.c @@ -70,6 +70,7 @@ struct tpm_inf_dev { u8 buf[TPM_BUFSIZE + sizeof(u8)]; /* max. buffer size + addr */ struct tpm_chip *chip; enum i2c_chip_type chip_type; + unsigned int adapterlimit; }; static struct tpm_inf_dev tpm_dev; @@ -111,6 +112,7 @@ static int iic_tpm_read(u8 addr, u8 *buffer, size_t len) int rc = 0; int count; + unsigned int msglen = len; /* Lock the adapter for the duration of the whole sequence. */ if (!tpm_dev.client->adapter->algo->master_xfer) @@ -131,27 +133,61 @@ static int iic_tpm_read(u8 addr, u8 *buffer, size_t len) usleep_range(SLEEP_DURATION_LOW, SLEEP_DURATION_HI); } } else { - /* slb9635 protocol should work in all cases */ - for (count = 0; count < MAX_COUNT; count++) { - rc = __i2c_transfer(tpm_dev.client->adapter, &msg1, 1); - if (rc > 0) - break; /* break here to skip sleep */ - - usleep_range(SLEEP_DURATION_LOW, SLEEP_DURATION_HI); - } - - if (rc <= 0) - goto out; - - /* After the TPM has successfully received the register address - * it needs some time, thus we're sleeping here again, before - * retrieving the data + /* Expect to send one command message and one data message, but + * support looping over each or both if necessary. */ - for (count = 0; count < MAX_COUNT; count++) { - usleep_range(SLEEP_DURATION_LOW, SLEEP_DURATION_HI); - rc = __i2c_transfer(tpm_dev.client->adapter, &msg2, 1); - if (rc > 0) - break; + while (len > 0) { + /* slb9635 protocol should work in all cases */ + for (count = 0; count < MAX_COUNT; count++) { + rc = __i2c_transfer(tpm_dev.client->adapter, + &msg1, 1); + if (rc > 0) + break; /* break here to skip sleep */ + + usleep_range(SLEEP_DURATION_LOW, + SLEEP_DURATION_HI); + } + + if (rc <= 0) + goto out; + + /* After the TPM has successfully received the register + * address it needs some time, thus we're sleeping here + * again, before retrieving the data + */ + for (count = 0; count < MAX_COUNT; count++) { + if (tpm_dev.adapterlimit) { + msglen = min_t(unsigned int, + tpm_dev.adapterlimit, + len); + msg2.len = msglen; + } + usleep_range(SLEEP_DURATION_LOW, + SLEEP_DURATION_HI); + rc = __i2c_transfer(tpm_dev.client->adapter, + &msg2, 1); + if (rc > 0) { + /* Since len is unsigned, make doubly + * sure we do not underflow it. + */ + if (msglen > len) + len = 0; + else + len -= msglen; + msg2.buf += msglen; + break; + } + /* If the I2C adapter rejected the request (e.g + * when the quirk read_max_len < len) fall back + * to a sane minimum value and try again. + */ + if (rc == -EOPNOTSUPP) + tpm_dev.adapterlimit = + I2C_SMBUS_BLOCK_MAX; + } + + if (rc <= 0) + goto out; } }