From: Alexander Sverdlin alexander.sverdlin@siemens.com
commit f3b70b6e3390bfdf18fdd7d278a72a12784fdcce upstream.
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 Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- drivers/char/tpm/tpm_tis_i2c.c | 37 ++++++++++++++++++++-------------- 1 file changed, 22 insertions(+), 15 deletions(-)
diff --git a/drivers/char/tpm/tpm_tis_i2c.c b/drivers/char/tpm/tpm_tis_i2c.c index c8c34adc14c0..106fd20d94e4 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)