[PATCH 2/2] tpm, tpm_tis: Reserve locality in tpm_tis_resume()

[Jarkko Sakkinen <jarkko@kernel.org>]

Reserve locality in tpm_tis_resume(), as it could be unsert after waking
up from a sleep state.

Reported-by: Hans de Goede <hdegoede@redhat.com>
Cc: Lino Sanfilippo <LinoSanfilippo@gmx.de>
Cc: stable@vger.kernel.org
Fixes: a3fbfae82b4c ("tpm: take TPM chip power gating out of tpm_transmit()")
Signed-off-by: Jarkko Sakkinen <jarkko@kernel.org>
---

v1:
* Testing done with Intel NUC5i5MYHE containing SLB9665 TPM 2.0 chip.
* The used test case: "echo mee | sudo tee /sys/power/state" executed
  without issues.

 drivers/char/tpm/tpm_tis_core.c | 12 ++++++++++--
 1 file changed, 10 insertions(+), 2 deletions(-)

diff --git a/drivers/char/tpm/tpm_tis_core.c b/drivers/char/tpm/tpm_tis_core.c
index 6fa150a3b75e..55b9d3965ae1 100644
--- a/drivers/char/tpm/tpm_tis_core.c
+++ b/drivers/char/tpm/tpm_tis_core.c
@@ -1125,12 +1125,20 @@ int tpm_tis_resume(struct device *dev)
 	if (ret)
 		return ret;
 
-	/* TPM 1.2 requires self-test on resume. This function actually returns
+	/*
+	 * TPM 1.2 requires self-test on resume. This function actually returns
 	 * an error code but for unknown reason it isn't handled.
 	 */
-	if (!(chip->flags & TPM_CHIP_FLAG_TPM2))
+	if (!(chip->flags & TPM_CHIP_FLAG_TPM2)) {
+		ret = request_locality(chip, 0);
+		if (ret < 0)
+			return ret;
+
 		tpm1_do_selftest(chip);
 
+		release_locality(chip, 0);
+	}
+
 	return 0;
 }
 EXPORT_SYMBOL_GPL(tpm_tis_resume);
-- 
2.31.1