From 292cf4a8a989cb564a6a5f0ba7a66e08a095afa1 Mon Sep 17 00:00:00 2001 From: Valdis Kletnieks <valdis.kletnieks@vt.edu> Date: Wed, 15 Oct 2008 22:04:35 -0700 Subject: [PATCH] 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> --- drivers/char/tpm/tpm.c | 7 +++++++ 1 file changed, 7 insertions(+) diff --git a/drivers/char/tpm/tpm.c b/drivers/char/tpm/tpm.c index 6b5a0e0127a70..aa899cec6b3f7 100644 --- a/drivers/char/tpm/tpm.c +++ b/drivers/char/tpm/tpm.c @@ -557,6 +557,13 @@ void tpm_get_timeouts(struct tpm_chip *chip) 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 + -- GitLab