diff options
Diffstat (limited to 'drivers/char/tpm/tpm.c')
| -rw-r--r-- | drivers/char/tpm/tpm.c | 31 |
1 files changed, 27 insertions, 4 deletions
diff --git a/drivers/char/tpm/tpm.c b/drivers/char/tpm/tpm.c index 0d2e82f95577..7c3b3dcbfbc8 100644 --- a/drivers/char/tpm/tpm.c +++ b/drivers/char/tpm/tpm.c @@ -1337,7 +1337,7 @@ int tpm_pm_suspend(struct device *dev) { struct tpm_chip *chip = dev_get_drvdata(dev); struct tpm_cmd_t cmd; - int rc; + int rc, try; u8 dummy_hash[TPM_DIGEST_SIZE] = { 0 }; @@ -1355,9 +1355,32 @@ int tpm_pm_suspend(struct device *dev) } /* now do the actual savestate */ - cmd.header.in = savestate_header; - rc = transmit_cmd(chip, &cmd, SAVESTATE_RESULT_SIZE, - "sending savestate before suspend"); + for (try = 0; try < TPM_RETRY; try++) { + cmd.header.in = savestate_header; + rc = transmit_cmd(chip, &cmd, SAVESTATE_RESULT_SIZE, NULL); + + /* + * If the TPM indicates that it is too busy to respond to + * this command then retry before giving up. It can take + * several seconds for this TPM to be ready. + * + * This can happen if the TPM has already been sent the + * SaveState command before the driver has loaded. TCG 1.2 + * specification states that any communication after SaveState + * may cause the TPM to invalidate previously saved state. + */ + if (rc != TPM_WARN_RETRY) + break; + msleep(TPM_TIMEOUT_RETRY); + } + + if (rc) + dev_err(chip->dev, + "Error (%d) sending savestate before suspend\n", rc); + else if (try > 0) + dev_warn(chip->dev, "TPM savestate took %dms\n", + try * TPM_TIMEOUT_RETRY); + return rc; } EXPORT_SYMBOL_GPL(tpm_pm_suspend); |