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: d1bd4a7 ("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]>
thirtythreeforty · Jun 24, 2019 · db4d8cb · db4d8cb
1 parent 6b03261
commit db4d8cb
Showing 1 changed file with 3 additions and 3 deletions.
diff --git 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;
 }