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@xxxxxxxxxxxxxxx Fixes: 30fc8d138e91 ("tpm: TPM 2.0 CRB Interface") Signed-off-by: Jarkko Sakkinen <jarkko.sakkinen@xxxxxxxxxxxxxxx> --- drivers/char/tpm/tpm_crb.c | 7 +++++-- 1 file changed, 5 insertions(+), 2 deletions(-) diff --git a/drivers/char/tpm/tpm_crb.c b/drivers/char/tpm/tpm_crb.c index 1b8e1b5..8819ef7 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) -- 2.7.4 -- To unsubscribe from this list: send the line "unsubscribe stable" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html