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authorJarkko Sakkinen <jarkko.sakkinen@linux.intel.com>2016-09-02 22:34:17 +0300
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2016-10-16 17:36:15 +0200
commit8866a28836924a0bfa84f1cbf574eb5138b7dec4 (patch)
tree37b7bf8f1e0b8dfa8b9f88c8129138a490bc5442
parentc0201ae6796a830fa7eb0cb537239102bedcbcc5 (diff)
tpm_crb: fix crb_req_canceled behavior
commit 72fd50e14e46dc0edf360631bdece87c2f066a97 upstream. 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. Fixes: 30fc8d138e91 ("tpm: TPM 2.0 CRB Interface") Signed-off-by: Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
-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 61e64293b765..2b21398c3adc 100644
--- a/drivers/char/tpm/tpm_crb.c
+++ b/drivers/char/tpm/tpm_crb.c
@@ -149,6 +149,11 @@ static int crb_send(struct tpm_chip *chip, u8 *buf, size_t len)
struct crb_priv *priv = chip->vendor.priv;
int rc = 0;
+ /* Zero the cancel register so that the next command will not get
+ * canceled.
+ */
+ iowrite32(0, &priv->cca->cancel);
+
if (len > le32_to_cpu(ioread32(&priv->cca->cmd_size))) {
dev_err(&chip->dev,
"invalid command count value %x %zx\n",
@@ -182,8 +187,6 @@ 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)