tpm: suppress durations sysfs output if not read
Suppress the output in the 'durations' sysfs entry if they were not read
during driver initialization. This is similar to other sysfs entries
that return nothing if for some reason sending the commands to the TPM
fails.
Signed-off-by: Stefan Berger <stefanb@linux.vnet.ibm.com>
Signed-off-by: James Morris <jmorris@namei.org>
diff --git a/drivers/char/tpm/tpm.c b/drivers/char/tpm/tpm.c
index caf8012..e53af76 100644
--- a/drivers/char/tpm/tpm.c
+++ b/drivers/char/tpm/tpm.c
@@ -963,6 +963,9 @@
{
struct tpm_chip *chip = dev_get_drvdata(dev);
+ if (chip->vendor.duration[TPM_LONG] == 0)
+ return 0;
+
return sprintf(buf, "%d %d %d [%s]\n",
jiffies_to_usecs(chip->vendor.duration[TPM_SHORT]),
jiffies_to_usecs(chip->vendor.duration[TPM_MEDIUM]),