[PATCH V2 05/12] tpm: Adjust interface timeouts if they are too small

From: Stefan Berger
Date: Wed Mar 30 2011 - 12:17:19 EST


Adjust the interface timeouts if they are found to be too small, i.e., if
they are returned in milliseconds rather than microseconds as we heared
from Infineon that some (old) Infineon TPMs do.

Signed-off-by: Stefan Berger <stefanb@xxxxxxxxxxxxxxxxxx>

---
drivers/char/tpm/tpm.c | 14 +++++++++-----
1 file changed, 9 insertions(+), 5 deletions(-)

Index: linux-2.6/drivers/char/tpm/tpm.c
===================================================================
--- linux-2.6.orig/drivers/char/tpm/tpm.c
+++ linux-2.6/drivers/char/tpm/tpm.c
@@ -534,6 +534,7 @@ void tpm_get_timeouts(struct tpm_chip *c
struct duration_t *duration_cap;
ssize_t rc;
u32 timeout;
+ unsigned int scale = 1;

tpm_cmd.header.in = tpm_getcap_header;
tpm_cmd.params.getcap_in.cap = TPM_CAP_PROP;
@@ -553,17 +554,21 @@ void tpm_get_timeouts(struct tpm_chip *c
timeout_cap = &tpm_cmd.params.getcap_out.cap.timeout;
/* Don't overwrite default if value is 0 */
timeout = be32_to_cpu(timeout_cap->a);
+ if (timeout && timeout < 1000) {
+ /* timeouts in msec rather usec */
+ scale = 1000;
+ }
if (timeout)
- chip->vendor.timeout_a = usecs_to_jiffies(timeout);
+ chip->vendor.timeout_a = usecs_to_jiffies(timeout * scale);
timeout = be32_to_cpu(timeout_cap->b);
if (timeout)
- chip->vendor.timeout_b = usecs_to_jiffies(timeout);
+ chip->vendor.timeout_b = usecs_to_jiffies(timeout * scale);
timeout = be32_to_cpu(timeout_cap->c);
if (timeout)
- chip->vendor.timeout_c = usecs_to_jiffies(timeout);
+ chip->vendor.timeout_c = usecs_to_jiffies(timeout * scale);
timeout = be32_to_cpu(timeout_cap->d);
if (timeout)
- chip->vendor.timeout_d = usecs_to_jiffies(timeout);
+ chip->vendor.timeout_d = usecs_to_jiffies(timeout * scale);

duration:
tpm_cmd.header.in = tpm_getcap_header;

--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/