[34-longterm 067/247] TPM: Long default timeout fix

Paul Gortmaker
2011-06-23T18:22:02Z

From: Rajiv Andrade <srajiv@linux.vnet.ibm.com>

-------------------
This is a commit scheduled for the next v2.6.34 longterm release.
If you see a problem with using this for longterm, please comment.
-------------------

commit c4ff4b829ef9e6353c0b133b7adb564a68054979 upstream.

If duration variable value is 0 at this point, it's because
chip->vendor.duration wasn't filled by tpm_get_timeouts() yet.
This patch sets then the lowest timeout just to give enough
time for tpm_get_timeouts() to further succeed.

This fix avoids long boot times in case another entity attempts
to send commands to the TPM when the TPM isn't accessible.

Signed-off-by: Rajiv Andrade <srajiv@linux.vnet.ibm.com>
Signed-off-by: James Morris <jmorris@namei.org>
Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
---
drivers/char/tpm/tpm.c | 10 ++++++----
1 files changed, 6 insertions(+), 4 deletions(-)

diff --git a/drivers/char/tpm/tpm.c b/drivers/char/tpm/tpm.c
index 068c816..6ab5381 100644
--- a/drivers/char/tpm/tpm.c
+++ b/drivers/char/tpm/tpm.c
@@ -354,12 +354,14 @@ unsigned long tpm_calc_ordinal_duration(struct tpm_chip *chip,
tpm_protected_ordinal_duration[ordinal &
TPM_PROTECTED_ORDINAL_MASK];

- if (duration_idx != TPM_UNDEFINED)
+ if (duration_idx != TPM_UNDEFINED) {
duration = chip->vendor.duration[duration_idx];
- if (duration <= 0)
+ /* if duration is 0, it's because chip->vendor.duration wasn't */
+ /* filled yet, so we set the lowest timeout just to give enough */
+ /* time for tpm_get_timeouts() to succeed */
+ return (duration <= 0 ? HZ : duration);
+ } else
return 2 * 60 * HZ;
- else
- return duration;
}
EXPORT_SYMBOL_GPL(tpm_calc_ordinal_duration);

--
1.7.4.4