[PATCH AUTOSEL 6.14 22/23] tpm: tis: Double the timeout B to 4s

Sasha Levin
2025-05-19T21:22:06Z

From: Michal Suchanek <msuchanek@suse.de>

[ Upstream commit 2f661f71fda1fc0c42b7746ca5b7da529eb6b5be ]

With some Infineon chips the timeouts in tpm_tis_send_data (both B and
C) can reach up to about 2250 ms.

Timeout C is retried since
commit de9e33df7762 ("tpm, tpm_tis: Workaround failed command reception on Infineon devices")

Timeout B still needs to be extended.

The problem is most commonly encountered with context related operation
such as load context/save context. These are issued directly by the
kernel, and there is no retry logic for them.

When a filesystem is set up to use the TPM for unlocking the boot fails,
and restarting the userspace service is ineffective. This is likely
because ignoring a load context/save context result puts the real TPM
state and the TPM state expected by the kernel out of sync.

Chips known to be affected:
tpm_tis IFX1522:00: 2.0 TPM (device-id 0x1D, rev-id 54)
Description: SLB9672
Firmware Revision: 15.22

tpm_tis MSFT0101:00: 2.0 TPM (device-id 0x1B, rev-id 22)
Firmware Revision: 7.83

tpm_tis MSFT0101:00: 2.0 TPM (device-id 0x1A, rev-id 16)
Firmware Revision: 5.63

Link: https://lore.kernel.org/linux-integrity/Z5pI07m0Muapyu9w@kitsune.suse.cz/
Signed-off-by: Michal Suchanek <msuchanek@suse.de>
Reviewed-by: Jarkko Sakkinen <jarkko@kernel.org>
Signed-off-by: Jarkko Sakkinen <jarkko@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
drivers/char/tpm/tpm_tis_core.h | 2 +-
include/linux/tpm.h | 2 +-
2 files changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/char/tpm/tpm_tis_core.h b/drivers/char/tpm/tpm_tis_core.h
index 970d02c337c7f..6c3aa480396b6 100644
--- a/drivers/char/tpm/tpm_tis_core.h
+++ b/drivers/char/tpm/tpm_tis_core.h
@@ -54,7 +54,7 @@ enum tis_int_flags {
enum tis_defaults {
TIS_MEM_LEN = 0x5000,
TIS_SHORT_TIMEOUT = 750, /* ms */
- TIS_LONG_TIMEOUT = 2000, /* 2 sec */
+ TIS_LONG_TIMEOUT = 4000, /* 4 secs */
TIS_TIMEOUT_MIN_ATML = 14700, /* usecs */
TIS_TIMEOUT_MAX_ATML = 15000, /* usecs */
};
diff --git a/include/linux/tpm.h b/include/linux/tpm.h
index 6c3125300c009..3db0b6a87d454 100644
--- a/include/linux/tpm.h
+++ b/include/linux/tpm.h
@@ -224,7 +224,7 @@ enum tpm2_const {

enum tpm2_timeouts {
TPM2_TIMEOUT_A = 750,
- TPM2_TIMEOUT_B = 2000,
+ TPM2_TIMEOUT_B = 4000,
TPM2_TIMEOUT_C = 200,
TPM2_TIMEOUT_D = 30,
TPM2_DURATION_SHORT = 20,
--
2.39.5