This is shown with Samsung Chromebook Pro (Caroline) with TPM 1.2 (SLB 9670):

[ 4.324298] TPM returned invalid status [ 4.324806] WARNING: CPU: 2 PID: 1 at drivers/char/tpm/tpm_tis_core.c:275 tpm_tis_status+0x86/0x8f

Background ==========

TCG PC Client Platform TPM Profile (PTP) Specification, paragraph 6.1 FIFO Interface Locality Usage per Register, Table 39 Register Behavior Based on Locality Setting for FIFO - a read attempt to TPM_STS_x Registers returns 0xFF in case of lack of locality.

The fix =======

Decorate tpm_get_timeouts() with request_locality() and release_locality().

Fixes: a3fbfae82b4c ("tpm: take TPM chip power gating out of tpm_transmit()") Cc: James Bottomley James.Bottomley@HansenPartnership.com Cc: Guenter Roeck linux@roeck-us.net Cc: Laurent Bigonville bigon@debian.org Cc: stable@vger.kernel.org Reported-by: Lukasz Majczak lma@semihalf.com Signed-off-by: Jarkko Sakkinen jarkko@kernel.org --- drivers/char/tpm/tpm_tis_core.c | 14 ++++++++++++-- 1 file changed, 12 insertions(+), 2 deletions(-)

diff --git a/drivers/char/tpm/tpm_tis_core.c b/drivers/char/tpm/tpm_tis_core.c index 431919d5f48a..30843954aa36 100644 --- a/drivers/char/tpm/tpm_tis_core.c +++ b/drivers/char/tpm/tpm_tis_core.c @@ -1019,11 +1019,21 @@ int tpm_tis_core_init(struct device *dev, struct tpm_tis_data *priv, int irq, init_waitqueue_head(&priv->read_queue); init_waitqueue_head(&priv->int_queue); if (irq != -1) { - /* Before doing irq testing issue a command to the TPM in polling mode + /* + * Before doing irq testing issue a command to the TPM in polling mode * to make sure it works. May as well use that command to set the * proper timeouts for the driver. */ - if (tpm_get_timeouts(chip)) { + + rc = request_locality(chip, 0); + if (rc < 0) + goto out_err; + + rc = tpm_get_timeouts(chip); + + release_locality(chip, 0); + + if (rc) { dev_err(dev, "Could not get TPM timeouts and durations\n"); rc = -ENODEV; goto out_err;