Messages in this thread Patch in this message |  | | From | Greg Kroah-Hartman <> | Subject | [PATCH 4.7 31/31] tpm_crb: fix crb_req_canceled behavior | Date | Fri, 14 Oct 2016 14:55:15 +0200 |
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4.7-stable review patch. If anyone has any objections, please let me know.
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From: Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com>
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>
--- drivers/char/tpm/tpm_crb.c | 7 +++++-- 1 file changed, 5 insertions(+), 2 deletions(-)
--- 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 *chi 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 > 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 * 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)
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