linux-kernel - [PATCH AUTOSEL 5.10 6/6] tpm: tis: Double the timeout B to 4s

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Message-Id: <20250519212320.1986749-6-sashal@kernel.org>
Date: Mon, 19 May 2025 17:23:20 -0400
From: Sasha Levin <sashal@...nel.org>
To: patches@...ts.linux.dev,
	stable@...r.kernel.org
Cc: Michal Suchanek <msuchanek@...e.de>,
	Jarkko Sakkinen <jarkko@...nel.org>,
	Sasha Levin <sashal@...nel.org>,
	peterhuewe@....de,
	jarkko.sakkinen@...ux.intel.com,
	gregkh@...uxfoundation.org,
	linux-integrity@...r.kernel.org,
	linux-kernel@...r.kernel.org
Subject: [PATCH AUTOSEL 5.10 6/6] tpm: tis: Double the timeout B to 4s

From: Michal Suchanek <msuchanek@...e.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@...e.de>
Reviewed-by: Jarkko Sakkinen <jarkko@...nel.org>
Signed-off-by: Jarkko Sakkinen <jarkko@...nel.org>
Signed-off-by: Sasha Levin <sashal@...nel.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 464ed352ab2e8..ed7b2caa9ebbd 100644
--- a/drivers/char/tpm/tpm_tis_core.h
+++ b/drivers/char/tpm/tpm_tis_core.h
@@ -53,7 +53,7 @@ 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 95c3069823f9b..7868e847eee0e 100644
--- a/include/linux/tpm.h
+++ b/include/linux/tpm.h
@@ -174,7 +174,7 @@ 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