tpm: Fix TPM 1.2 Shutdown sequence to prevent future TPM operations

TPM 2.0 Shutdown involve sending TPM2_Shutdown to TPM chip and disabling
future TPM operations. TPM 1.2 behavior was different, future TPM
operations weren't disabled, causing rare issues. This patch ensures
that future TPM operations are disabled.

Fixes: d1bd4a792d39 ("tpm: Issue a TPM2_Shutdown for TPM2 devices.")
Cc: [email protected]
Signed-off-by: Vadim Sukhomlinov <[email protected]>
[dianders: resolved merge conflicts with mainline]
Signed-off-by: Douglas Anderson <[email protected]>
Reviewed-by: Jarkko Sakkinen <[email protected]>
Signed-off-by: Jarkko Sakkinen <[email protected]>

1 files changed, 3 insertions, 3 deletions

diff --git a/drivers/char/tpm/tpm-chip.c b/drivers/char/tpm/tpm-chip.c
index 90325e1749fb..d47ad10a35fe 100644
--- a/drivers/char/tpm/tpm-chip.c
+++ b/drivers/char/tpm/tpm-chip.c
@@ -289,15 +289,15 @@ static int tpm_class_shutdown(struct device *dev)
 {
 	struct tpm_chip *chip = container_of(dev, struct tpm_chip, dev);
 
+	down_write(&chip->ops_sem);
 	if (chip->flags & TPM_CHIP_FLAG_TPM2) {
-		down_write(&chip->ops_sem);
 		if (!tpm_chip_start(chip)) {
 			tpm2_shutdown(chip, TPM2_SU_CLEAR);
 			tpm_chip_stop(chip);
 		}
-		chip->ops = NULL;
-		up_write(&chip->ops_sem);
 	}
+	chip->ops = NULL;
+	up_write(&chip->ops_sem);
 
 	return 0;
 }