[PATCH V2 02/12] tpm: Adjust the durations if they are too small

[Stefan Berger]

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@xxxxxxxxxxxxxxxxxx>

---
 drivers/char/tpm/tpm.c |   17 +++++++++++------
 1 file changed, 11 insertions(+), 6 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
@@ -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);
 

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