tpm: Adjust the durations if they are too small
Stefan Berger [Wed, 30 Mar 2011 16:13:24 +0000 (12:13 -0400)]
Adjust the durations if they are found to be too small, i.e., if they are
returned in milliseconds rather than microseconds as some Infineon TPMs are
reported to do.

Signed-off-by: Stefan Berger <stefanb@linux.vnet.ibm.com>
Signed-off-by: Rajiv Andrade <srajiv@linux.vnet.ibm.com>

drivers/char/tpm/tpm.c

index aebb4b5..277cf22 100644 (file)
@@ -583,17 +583,22 @@ duration:
        duration_cap = &tpm_cmd.params.getcap_out.cap.duration;
        chip->vendor.duration[TPM_SHORT] =
            usecs_to_jiffies(be32_to_cpu(duration_cap->tpm_short));
+       chip->vendor.duration[TPM_MEDIUM] =
+           usecs_to_jiffies(be32_to_cpu(duration_cap->tpm_medium));
+       chip->vendor.duration[TPM_LONG] =
+           usecs_to_jiffies(be32_to_cpu(duration_cap->tpm_long));
+
        /* 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.
+        * We also scale the TPM_MEDIUM and -_LONG values by 1000.
         */
-       if (chip->vendor.duration[TPM_SHORT] < (HZ/100))
+       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(duration_cap->tpm_medium));
-       chip->vendor.duration[TPM_LONG] =
-           usecs_to_jiffies(be32_to_cpu(duration_cap->tpm_long));
+               chip->vendor.duration[TPM_MEDIUM] *= 1000;
+               chip->vendor.duration[TPM_LONG] *= 1000;
+               dev_info(chip->dev, "Adjusting TPM timeout parameters.");
+       }
 }
 EXPORT_SYMBOL_GPL(tpm_get_timeouts);