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| author | Alexander Sverdlin <alexander.sverdlin@siemens.com> | 2023-05-24 17:40:39 +0200 |
|---|---|---|
| committer | Jarkko Sakkinen <jarkko@kernel.org> | 2023-07-17 19:32:30 +0000 |
| commit | f3b70b6e3390bfdf18fdd7d278a72a12784fdcce (patch) | |
| tree | cec62f897cf2f32d8928759d2dbb442a71f9fd61 /drivers/char/tpm | |
| parent | f0afba4042bd902d290405c0638bc1295872d8a7 (diff) | |
| download | linux-f3b70b6e3390bfdf18fdd7d278a72a12784fdcce.tar.gz | |
tpm: tis_i2c: Limit read bursts to I2C_SMBUS_BLOCK_MAX (32) bytes
Underlying I2C bus drivers not always support longer transfers and
imx-lpi2c for instance doesn't. SLB 9673 offers 427-bytes packets.
Visible symptoms are:
tpm tpm0: Error left over data
tpm tpm0: tpm_transmit: tpm_recv: error -5
tpm_tis_i2c: probe of 1-002e failed with error -5
Cc: stable@vger.kernel.org # v5.20+
Fixes: bbc23a07b072 ("tpm: Add tpm_tis_i2c backend for tpm_tis_core")
Tested-by: Michael Haener <michael.haener@siemens.com>
Signed-off-by: Alexander Sverdlin <alexander.sverdlin@siemens.com>
Reviewed-by: Jarkko Sakkinen <jarkko@kernel.org>
Reviewed-by: Jerry Snitselaar <jsnitsel@redhat.com>
Signed-off-by: Jarkko Sakkinen <jarkko@kernel.org>
Diffstat (limited to 'drivers/char/tpm')
| -rw-r--r-- | drivers/char/tpm/tpm_tis_i2c.c | 37 |
1 files changed, 22 insertions, 15 deletions
diff --git a/drivers/char/tpm/tpm_tis_i2c.c b/drivers/char/tpm/tpm_tis_i2c.c index c8c34adc14c0e..106fd20d94e4f 100644 --- a/drivers/char/tpm/tpm_tis_i2c.c +++ b/drivers/char/tpm/tpm_tis_i2c.c @@ -189,21 +189,28 @@ static int tpm_tis_i2c_read_bytes(struct tpm_tis_data *data, u32 addr, u16 len, int ret; for (i = 0; i < TPM_RETRY; i++) { - /* write register */ - msg.len = sizeof(reg); - msg.buf = ® - msg.flags = 0; - ret = tpm_tis_i2c_retry_transfer_until_ack(data, &msg); - if (ret < 0) - return ret; - - /* read data */ - msg.buf = result; - msg.len = len; - msg.flags = I2C_M_RD; - ret = tpm_tis_i2c_retry_transfer_until_ack(data, &msg); - if (ret < 0) - return ret; + u16 read = 0; + + while (read < len) { + /* write register */ + msg.len = sizeof(reg); + msg.buf = ® + msg.flags = 0; + ret = tpm_tis_i2c_retry_transfer_until_ack(data, &msg); + if (ret < 0) + return ret; + + /* read data */ + msg.buf = result + read; + msg.len = len - read; + msg.flags = I2C_M_RD; + if (msg.len > I2C_SMBUS_BLOCK_MAX) + msg.len = I2C_SMBUS_BLOCK_MAX; + ret = tpm_tis_i2c_retry_transfer_until_ack(data, &msg); + if (ret < 0) + return ret; + read += msg.len; + } ret = tpm_tis_i2c_sanity_check_read(reg, len, result); if (ret == 0) |