linux-kernel - [225/272] TPM: Long default timeout fix

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Message-Id: <20110216001447.619414869@clark.kroah.org>
Date:	Tue, 15 Feb 2011 16:14:42 -0800
From:	Greg KH <gregkh@...e.de>
To:	linux-kernel@...r.kernel.org, stable@...nel.org
Cc:	stable-review@...nel.org, torvalds@...ux-foundation.org,
	akpm@...ux-foundation.org, alan@...rguk.ukuu.org.uk,
	Rajiv Andrade <srajiv@...ux.vnet.ibm.com>,
	James Morris <jmorris@...ei.org>
Subject: [225/272] TPM: Long default timeout fix

2.6.37-stable review patch.  If anyone has any objections, please let us know.

------------------

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

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@...ux.vnet.ibm.com>
Signed-off-by: James Morris <jmorris@...ei.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@...e.de>

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

--- a/drivers/char/tpm/tpm.c
+++ b/drivers/char/tpm/tpm.c
@@ -364,12 +364,14 @@ unsigned long tpm_calc_ordinal_duration(
 		    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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