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tpm: Adjust the durations if they are too small

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Adjust the durations if they are found to be too small, i.e., if they are
returned in milliseconds rather than microseconds as some Infineon TPMs are
reported to do.

Signed-off-by: Stefan Berger <stefanb@linux.vnet.ibm.com>
Signed-off-by: Rajiv Andrade <srajiv@linux.vnet.ibm.com>
This commit is contained in:
Stefan Berger 2011-03-30 12:13:24 -04:00 committed by Rajiv Andrade
parent 979b140614
commit e934acca1e
1 changed files with 12 additions and 7 deletions
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19
drivers/char/tpm/tpm.c
View file

@ -583,17 +583,22 @@ duration:
duration_cap = &tpm_cmd.params.getcap_out.cap.duration;
chip->vendor.duration[TPM_SHORT] =
usecs_to_jiffies(be32_to_cpu(duration_cap->tpm_short));
/* The Broadcom BCM0102 chipset in a Dell Latitude D820 gets the above
* value wrong and apparently reports msecs rather than usecs. So we
* fix up the resulting too-small TPM_SHORT value to make things work.
*/
if (chip->vendor.duration[TPM_SHORT] < (HZ/100))
chip->vendor.duration[TPM_SHORT] = HZ;
chip->vendor.duration[TPM_MEDIUM] =
usecs_to_jiffies(be32_to_cpu(duration_cap->tpm_medium));
chip->vendor.duration[TPM_LONG] =
usecs_to_jiffies(be32_to_cpu(duration_cap->tpm_long));
/* The Broadcom BCM0102 chipset in a Dell Latitude D820 gets the above
* value wrong and apparently reports msecs rather than usecs. So we
* fix up the resulting too-small TPM_SHORT value to make things work.
* We also scale the TPM_MEDIUM and -_LONG values by 1000.
*/
if (chip->vendor.duration[TPM_SHORT] < (HZ / 100)) {
chip->vendor.duration[TPM_SHORT] = HZ;
chip->vendor.duration[TPM_MEDIUM] *= 1000;
chip->vendor.duration[TPM_LONG] *= 1000;
dev_info(chip->dev, "Adjusting TPM timeout parameters.");
}
}
EXPORT_SYMBOL_GPL(tpm_get_timeouts);