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authorValdis Kletnieks <valdis.kletnieks@vt.edu>2008-10-15 22:04:35 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2008-10-16 11:21:49 -0700
commit292cf4a8a989cb564a6a5f0ba7a66e08a095afa1 (patch)
tree6db1701350102a4ee9aa19aac366e166db475a48 /drivers/char/tpm
parent9e5b1b12226d5a501fbc6706ca090e00d18a01ad (diff)
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tpm: work around bug in Broadcom BCM0102 chipset
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@vt.edu> Cc: 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> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'drivers/char/tpm')
-rw-r--r--drivers/char/tpm/tpm.c7
1 files changed, 7 insertions, 0 deletions
diff --git a/drivers/char/tpm/tpm.c b/drivers/char/tpm/tpm.c
index 6b5a0e0127a7..aa899cec6b3f 100644
--- a/drivers/char/tpm/tpm.c
+++ b/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 +