The patch titled
tpm: work around bug in Broadcom BCM0102 chipset
has been added to the -mm tree. Its filename is
tpm-work-around-bug-in-broadcom-bcm0102-chipset.patch
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------------------------------------------------------
Subject: tpm: work around bug in Broadcom BCM0102 chipset
From: Valdis.Kletnieks@xxxxxx
Patch tpm-correct-tpm-timeouts-to-jiffies-conversion reveals a bug in the
Broadcom BCM0102 TPM chipset used in the Dell Latitude D820 - although
most of the timeouts are returned in usecs as per the spec, one is
apparently returned in msecs, which results in a too-small value leading
to a timeout when the code treats it as usecs. To prevent a regression,
we check for the known too-short value and adjust it to a value that makes
things work.
Signed-off-by: Valdis Kletnieks <valdis.kletnieks@xxxxxx>
Cc: Marcin Obara <marcin_obara@xxxxxxxxxxxxxxxxxxxxx>
Cc: Marcel Selhorst <tpm@xxxxxxxxxxxx>
Cc: Kylene Jo Hall <kjhall@xxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
drivers/char/tpm/tpm.c | 7 +++++++
1 file changed, 7 insertions(+)
diff -puN drivers/char/tpm/tpm.c~tpm-work-around-bug-in-broadcom-bcm0102-chipset drivers/char/tpm/tpm.c
--- a/drivers/char/tpm/tpm.c~tpm-work-around-bug-in-broadcom-bcm0102-chipset
+++ a/drivers/char/tpm/tpm.c
@@ -557,6 +557,13 @@ duration:
usecs_to_jiffies(be32_to_cpu
(*((__be32 *) (data +
TPM_GET_CAP_RET_UINT32_1_IDX))));
+ /* The Broadcom BCM0102 chipset in a Dell Latitude D820 gets the above
+ * value wrong and apparently reports msecs rather than usecs. So we
+ * fix up the resulting too-small TPM_SHORT value to make things work.
+ */
+ if (chip->vendor.duration[TPM_SHORT] < (HZ/100))
+ chip->vendor.duration[TPM_SHORT] = HZ;
+
chip->vendor.duration[TPM_MEDIUM] =
usecs_to_jiffies(be32_to_cpu
(*((__be32 *) (data +
_
Patches currently in -mm which might be from valdis.kletnieks@xxxxxx are
tpm-work-around-bug-in-broadcom-bcm0102-chipset.patch
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