summaryrefslogtreecommitdiff
path: root/drivers
diff options
context:
space:
mode:
authorAlexander Sverdlin <alexander.sverdlin@siemens.com>2023-05-24 17:40:39 +0200
committerJarkko Sakkinen <jarkko@kernel.org>2023-07-17 19:32:30 +0000
commitf3b70b6e3390bfdf18fdd7d278a72a12784fdcce (patch)
treecec62f897cf2f32d8928759d2dbb442a71f9fd61 /drivers
parentf0afba4042bd902d290405c0638bc1295872d8a7 (diff)
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')
-rw-r--r--drivers/char/tpm/tpm_tis_i2c.c37
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 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 = &reg;
- 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 = &reg;
+ 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)