tpm, tpm_tis: Decorate tpm_tis_gen_interrupt() with request_locality()

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_tis_gen_interrupt() with request_locality() and
release_locality().

Cc: Laurent Bigonville <[email protected]>
Cc: James Bottomley <[email protected]>
Cc: Guenter Roeck <[email protected]>
Cc: [email protected]
Fixes: a3fbfae82b4c ("tpm: take TPM chip power gating out of tpm_transmit()")
Signed-off-by: Lukasz Majczak <[email protected]>
Signed-off-by: Jarkko Sakkinen <[email protected]>

diff --git a/drivers/char/tpm/tpm_tis_core.c b/drivers/char/tpm/tpm_tis_core.c
index 30843954aa365ef92cdbf925401ba8e33194cb5e..a2e0395cbe618d8a86604c854a0e46dccca40be3 100644 (file)
--- a/drivers/char/tpm/tpm_tis_core.c
+++ b/drivers/char/tpm/tpm_tis_core.c
@@ -707,12 +707,22 @@ static int tpm_tis_gen_interrupt(struct tpm_chip *chip)
        const char *desc = "attempting to generate an interrupt";
        u32 cap2;
        cap_t cap;
+       int ret;
 
+       /* TPM 2.0 */
        if (chip->flags & TPM_CHIP_FLAG_TPM2)
                return tpm2_get_tpm_pt(chip, 0x100, &cap2, desc);
-       else
-               return tpm1_getcap(chip, TPM_CAP_PROP_TIS_TIMEOUT, &cap, desc,
-                                 0);
+
+       /* TPM 1.2 */
+       ret = request_locality(chip, 0);
+       if (ret < 0)
+               return ret;
+
+       ret = tpm1_getcap(chip, TPM_CAP_PROP_TIS_TIMEOUT, &cap, desc, 0);
+
+       release_locality(chip, 0);
+
+       return ret;
 }
 
 /* Register the IRQ and issue a command that will cause an interrupt. If an