diff options
Diffstat (limited to 'drivers/char/tpm')
| -rw-r--r-- | drivers/char/tpm/tpm_tis_core.c | 37 | ||||
| -rw-r--r-- | drivers/char/tpm/tpm_tis_core.h | 1 |
2 files changed, 30 insertions, 8 deletions
diff --git a/drivers/char/tpm/tpm_tis_core.c b/drivers/char/tpm/tpm_tis_core.c index 469e4cd7fb4a..52e2dc7a9f81 100644 --- a/drivers/char/tpm/tpm_tis_core.c +++ b/drivers/char/tpm/tpm_tis_core.c @@ -340,7 +340,7 @@ static int recv_data(struct tpm_chip *chip, u8 *buf, size_t count) return size; } -static int tpm_tis_recv(struct tpm_chip *chip, u8 *buf, size_t count) +static int tpm_tis_try_recv(struct tpm_chip *chip, u8 *buf, size_t count) { struct tpm_tis_data *priv = dev_get_drvdata(&chip->dev); int size = 0; @@ -348,11 +348,6 @@ static int tpm_tis_recv(struct tpm_chip *chip, u8 *buf, size_t count) u32 expected; int rc; - if (count < TPM_HEADER_SIZE) { - size = -EIO; - goto out; - } - size = recv_data(chip, buf, TPM_HEADER_SIZE); /* read first 10 bytes, including tag, paramsize, and result */ if (size < TPM_HEADER_SIZE) { @@ -385,7 +380,7 @@ static int tpm_tis_recv(struct tpm_chip *chip, u8 *buf, size_t count) goto out; } status = tpm_tis_status(chip); - if (status & TPM_STS_DATA_AVAIL) { /* retry? */ + if (status & TPM_STS_DATA_AVAIL) { dev_err(&chip->dev, "Error left over data\n"); size = -EIO; goto out; @@ -399,10 +394,36 @@ static int tpm_tis_recv(struct tpm_chip *chip, u8 *buf, size_t count) } out: - tpm_tis_ready(chip); return size; } +static int tpm_tis_recv(struct tpm_chip *chip, u8 *buf, size_t count) +{ + struct tpm_tis_data *priv = dev_get_drvdata(&chip->dev); + unsigned int try; + int rc = 0; + + if (count < TPM_HEADER_SIZE) + return -EIO; + + for (try = 0; try < TPM_RETRY; try++) { + rc = tpm_tis_try_recv(chip, buf, count); + + if (rc == -EIO) + /* Data transfer errors, indicated by EIO, can be + * recovered by rereading the response. + */ + tpm_tis_write8(priv, TPM_STS(priv->locality), + TPM_STS_RESPONSE_RETRY); + else + break; + } + + tpm_tis_ready(chip); + + return rc; +} + /* * If interrupts are used (signaled by an irq set in the vendor structure) * tpm.c can skip polling for the data to be available as the interrupt is diff --git a/drivers/char/tpm/tpm_tis_core.h b/drivers/char/tpm/tpm_tis_core.h index b1a169d7d1ca..13e99cf65efe 100644 --- a/drivers/char/tpm/tpm_tis_core.h +++ b/drivers/char/tpm/tpm_tis_core.h @@ -34,6 +34,7 @@ enum tis_status { TPM_STS_GO = 0x20, TPM_STS_DATA_AVAIL = 0x10, TPM_STS_DATA_EXPECT = 0x08, + TPM_STS_RESPONSE_RETRY = 0x02, TPM_STS_READ_ZERO = 0x23, /* bits that must be zero on read */ }; |