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DateMon, 11 Aug 2008 13:44:13 -0700
FromAndrew Morton <>
SubjectRe: [PATCH] 2.6.26-mmotm tpm-correct-tpm-timeouts-to-jiffies-conversion-d820-fix.patch
On Sat, 26 Jul 2008 20:27:33 +0100
"Marcin Obara" <marcin_obara@users.sourceforge.net> wrote:

> 2008/7/26 <Valdis.Kletnieks@vt.edu>:
> > + if (chip->vendor.duration[TPM_SHORT] == 1)
> > + chip->vendor.duration[TPM_SHORT] *= 1000;
> > +
> > chip->vendor.duration[TPM_MEDIUM] =
> > usecs_to_jiffies(be32_to_cpu
> > (*((__be32 *) (data +
>
>
> Value in chip->vendor.duration[TPM_SHORT] is in jiffies not in milliseconds.
> (As I know it's not the same. Jiffy is in range 1-10 ms.)
> I know the result may be the same, but it is unclear.
>
> Maybe... value should be compared (to 1000) before conversion?
> or...
> If after conversion, there should be something like this:
> if (chip->vendor.duration[TPM_SHORT] < (HZ/100)) /* less
> than 10ms ? */
> chip->vendor.duration[TPM_SHORT] = HZ;
>
> What do you think?
>

This all seemed to die off without a conclusion.

Here's the current
tpm-correct-tpm-timeouts-to-jiffies-conversion.patch. Does it need
updating?

Thanks.


From: Marcin Obara <marcin_obara@users.sourceforge.net>

This patch fixes timeouts conversion to jiffies, by replacing
msecs_to_jiffies() calls with usecs_to_jiffies(). According to TCG TPM
Specification Version 1.2 Revision 103 (pages 166, 167) TPM timeouts and
durations are returned in microseconds (usec) not in miliseconds (msec).

Signed-off-by: Marcin Obara <marcin_obara@users.sourceforge.net>
Cc: Marcel Selhorst <tpm@selhorst.net>
Cc: Kylene Jo Hall <kjhall@us.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
---
drivers/char/tpm/tpm.c | 14 +++++++-------
1 file changed, 7 insertions(+), 7 deletions(-)
diff -puN drivers/char/tpm/tpm.c~tpm-correct-tpm-timeouts-to-jiffies-conversion drivers/char/tpm/tpm.c
--- a/drivers/char/tpm/tpm.c~tpm-correct-tpm-timeouts-to-jiffies-conversion
+++ a/drivers/char/tpm/tpm.c
@@ -525,19 +525,19 @@ void tpm_get_timeouts(struct tpm_chip *c
timeout =
be32_to_cpu(*((__be32 *) (data + TPM_GET_CAP_RET_UINT32_1_IDX)));
if (timeout)
- chip->vendor.timeout_a = msecs_to_jiffies(timeout);
+ chip->vendor.timeout_a = usecs_to_jiffies(timeout);
timeout =
be32_to_cpu(*((__be32 *) (data + TPM_GET_CAP_RET_UINT32_2_IDX)));
if (timeout)
- chip->vendor.timeout_b = msecs_to_jiffies(timeout);
+ chip->vendor.timeout_b = usecs_to_jiffies(timeout);
timeout =
be32_to_cpu(*((__be32 *) (data + TPM_GET_CAP_RET_UINT32_3_IDX)));
if (timeout)
- chip->vendor.timeout_c = msecs_to_jiffies(timeout);
+ chip->vendor.timeout_c = usecs_to_jiffies(timeout);
timeout =
be32_to_cpu(*((__be32 *) (data + TPM_GET_CAP_RET_UINT32_4_IDX)));
if (timeout)
- chip->vendor.timeout_d = msecs_to_jiffies(timeout);
+ chip->vendor.timeout_d = usecs_to_jiffies(timeout);

duration:
memcpy(data, tpm_cap, sizeof(tpm_cap));
@@ -554,15 +554,15 @@ duration:
return;

chip->vendor.duration[TPM_SHORT] =
- msecs_to_jiffies(be32_to_cpu
+ usecs_to_jiffies(be32_to_cpu
(*((__be32 *) (data +
TPM_GET_CAP_RET_UINT32_1_IDX))));
chip->vendor.duration[TPM_MEDIUM] =
- msecs_to_jiffies(be32_to_cpu
+ usecs_to_jiffies(be32_to_cpu
(*((__be32 *) (data +
TPM_GET_CAP_RET_UINT32_2_IDX))));
chip->vendor.duration[TPM_LONG] =
- msecs_to_jiffies(be32_to_cpu
+ usecs_to_jiffies(be32_to_cpu
(*((__be32 *) (data +
TPM_GET_CAP_RET_UINT32_3_IDX))));
}
_


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