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authorStefan Berger <stefanb@linux.vnet.ibm.com>2011-03-30 18:13:24 +0200
committerRajiv Andrade <srajiv@linux.vnet.ibm.com>2011-07-12 23:53:07 +0200
commite934acca1ee993e1d99d7dc203569a6e5cdfb392 (patch)
treee0ac7a2305c0b2633a798721e5fe5b95c6d89d98 /drivers/char
parenttpm: Use durations returned from TPM (diff)
downloadlinux-e934acca1ee993e1d99d7dc203569a6e5cdfb392.tar.xz
linux-e934acca1ee993e1d99d7dc203569a6e5cdfb392.zip
tpm: Adjust the durations if they are too small
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>
Diffstat (limited to 'drivers/char')
-rw-r--r--drivers/char/tpm/tpm.c17
1 files changed, 11 insertions, 6 deletions
diff --git a/drivers/char/tpm/tpm.c b/drivers/char/tpm/tpm.c
index aebb4b5a199c..277cf22609ca 100644
--- a/drivers/char/tpm/tpm.c
+++ b/drivers/char/tpm/tpm.c
@@ -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));
+ 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))
+ 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));
+ 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);