From: Enric Balletbo i Serra <enric.balletbo@collabora.com>
To: Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com>,
Peter Huewe <peterhuewe@gmx.de>
Cc: wsa@the-dreams.de, Andrew Lunn <andrew@lunn.ch>,
linux-kernel@vger.kernel.org, tpmdd-devel@lists.sourceforge.net,
Bryan Freed <bfreed@chromium.org>
Subject: [PATCH v3] tpm: Apply a sane minimum adapterlimit value for retransmission.
Date: Mon, 22 May 2017 11:20:11 +0200 [thread overview]
Message-ID: <20170522092011.8937-1-enric.balletbo@collabora.com> (raw)
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>
Acked-by: Andrew Lunn <andrew@lunn.ch>
Reviewed-by: Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com>
Reviewed-by: Andrew Lunn <andrew@lunn.ch>
---
The purpose of this resend is only a reminder for if this can be accepted
for the next merge window as I missed last merge. Thanks.
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 dc47fa2..79d6bbb 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
next reply other threads:[~2017-05-22 9:20 UTC|newest]
Thread overview: 10+ messages / expand[flat|nested] mbox.gz Atom feed top
2017-05-22 9:20 Enric Balletbo i Serra [this message]
2017-05-24 19:10 ` [PATCH v3] tpm: Apply a sane minimum adapterlimit value for retransmission Jarkko Sakkinen
-- strict thread matches above, loose matches on Subject: below --
2017-03-28 15:29 Enric Balletbo i Serra
[not found] ` <20170328152938.14539-1-enric.balletbo-ZGY8ohtN/8qB+jHODAdFcQ@public.gmane.org>
2017-03-28 16:20 ` Andrew Lunn
2017-03-31 8:13 ` Jarkko Sakkinen
2017-04-05 9:03 ` Jarkko Sakkinen
[not found] ` <20170405090327.pssnm3mjcpajpoy6-ral2JQCrhuEAvxtiuMwx3w@public.gmane.org>
2017-04-05 10:05 ` Peter Huewe
[not found] ` <384D02FC-BCCF-45F0-896D-058326EC6783-Mmb7MZpHnFY@public.gmane.org>
2017-04-05 13:37 ` Jarkko Sakkinen
2017-04-05 13:24 ` Andrew Lunn
[not found] ` <20170405132431.GA11583-g2DYL2Zd6BY@public.gmane.org>
2017-04-05 13:35 ` Jarkko Sakkinen
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