summaryrefslogtreecommitdiff
path: root/drivers/char
diff options
context:
space:
mode:
authorJarkko Sakkinen <jarkko.sakkinen@linux.intel.com>2016-09-02 22:34:17 +0300
committerJarkko Sakkinen <jarkko.sakkinen@linux.intel.com>2016-09-15 16:04:21 +0300
commit72fd50e14e46dc0edf360631bdece87c2f066a97 (patch)
tree6a4d066f4669c8833f37da1dbed27ac65e2221fc /drivers/char
parent0c541332231e7957f23013e37f3720db33e7804c (diff)
tpm_crb: fix crb_req_canceled behavior
The req_canceled() callback is used by tpm_transmit() periodically to check whether the request has been canceled while it is receiving a response from the TPM. The TPM_CRB_CTRL_CANCEL register was cleared already in the crb_cancel callback, which has two consequences: * Cancel might not happen. * req_canceled() always returns zero. A better place to clear the register is when starting to send a new command. The behavior of TPM_CRB_CTRL_CANCEL is described in the section 5.5.3.6 of the PTP specification. CC: stable@vger.kernel.org Fixes: 30fc8d138e91 ("tpm: TPM 2.0 CRB Interface") Signed-off-by: Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com>
Diffstat (limited to 'drivers/char')
-rw-r--r--drivers/char/tpm/tpm_crb.c7
1 files changed, 5 insertions, 2 deletions
diff --git a/drivers/char/tpm/tpm_crb.c b/drivers/char/tpm/tpm_crb.c
index 018c382554ba..1801f382377e 100644
--- a/drivers/char/tpm/tpm_crb.c
+++ b/drivers/char/tpm/tpm_crb.c
@@ -142,6 +142,11 @@ static int crb_send(struct tpm_chip *chip, u8 *buf, size_t len)
struct crb_priv *priv = dev_get_drvdata(&chip->dev);
int rc = 0;
+ /* Zero the cancel register so that the next command will not get
+ * canceled.
+ */
+ iowrite32(0, &priv->cca->cancel);
+
if (len > ioread32(&priv->cca->cmd_size)) {
dev_err(&chip->dev,
"invalid command count value %x %zx\n",
@@ -175,8 +180,6 @@ static void crb_cancel(struct tpm_chip *chip)
if ((priv->flags & CRB_FL_ACPI_START) && crb_do_acpi_start(chip))
dev_err(&chip->dev, "ACPI Start failed\n");
-
- iowrite32(0, &priv->cca->cancel);
}
static bool crb_req_canceled(struct tpm_chip *chip, u8 status)