TPM: Long default timeout fix
Rajiv Andrade [Fri, 12 Nov 2010 21:30:02 +0000 (22:30 +0100)]
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>

drivers/char/tpm/tpm.c

index 1f46f1c..36e0fa1 100644 (file)
@@ -364,12 +364,14 @@ 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);