From 280db21e153d8810ce3b93640c63ae922bcb9e8e Mon Sep 17 00:00:00 2001 From: Alexander Steffen Date: Tue, 13 Jun 2023 20:02:59 +0200 Subject: [PATCH] tpm_tis: Resend command to recover from data transfer errors Similar to the transmission of TPM responses, also the transmission of TPM commands may become corrupted. Instead of aborting when detecting such issues, try resending the command again. Signed-off-by: Alexander Steffen Reviewed-by: Jarkko Sakkinen Signed-off-by: Jarkko Sakkinen --- drivers/char/tpm/tpm_tis_core.c | 13 ++++++++++--- 1 file changed, 10 insertions(+), 3 deletions(-) diff --git a/drivers/char/tpm/tpm_tis_core.c b/drivers/char/tpm/tpm_tis_core.c index 52e2dc7a9f81..1b350412d8a6 100644 --- a/drivers/char/tpm/tpm_tis_core.c +++ b/drivers/char/tpm/tpm_tis_core.c @@ -539,10 +539,17 @@ static int tpm_tis_send_main(struct tpm_chip *chip, const u8 *buf, size_t len) int rc; u32 ordinal; unsigned long dur; + unsigned int try; - rc = tpm_tis_send_data(chip, buf, len); - if (rc < 0) - return rc; + for (try = 0; try < TPM_RETRY; try++) { + rc = tpm_tis_send_data(chip, buf, len); + if (rc >= 0) + /* Data transfer done successfully */ + break; + else if (rc != -EIO) + /* Data transfer failed, not recoverable */ + return rc; + } /* go and do it */ rc = tpm_tis_write8(priv, TPM_STS(priv->locality), TPM_STS_GO);