[PATCH] [72/275] TPM: Long default timeout fix

[Andi Kleen]

2.6.35-longterm review patch.  If anyone has any objections, please let me know.

------------------
From: Rajiv Andrade <srajiv@xxxxxxxxxxxxxxxxxx>

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@xxxxxxxxxxxxxxxxxx>
Signed-off-by: James Morris <jmorris@xxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxx>
Signed-off-by: Andi Kleen <ak@xxxxxxxxxxxxxxx>

---
 drivers/char/tpm/tpm.c |   10 ++++++----
 1 file changed, 6 insertions(+), 4 deletions(-)

Index: linux-2.6.35.y/drivers/char/tpm/tpm.c
===================================================================
--- linux-2.6.35.y.orig/drivers/char/tpm/tpm.c	2011-03-29 22:51:41.259667437 -0700
+++ linux-2.6.35.y/drivers/char/tpm/tpm.c	2011-03-29 23:55:12.337151500 -0700
@@ -354,12 +354,14 @@
 		    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);
 
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