Update Linux to v5.4.148

Sourced from [1]

[1] https://cdn.kernel.org/pub/linux/kernel/v5.x/linux-5.4.148.tar.gz

Change-Id: Ib3d26c5ba9b022e2e03533005c4fed4d7c30b61b
Signed-off-by: Olivier Deprez <olivier.deprez@arm.com>
diff --git a/drivers/char/tpm/tpm-dev-common.c b/drivers/char/tpm/tpm-dev-common.c
index 2ec47a6..1784530 100644
--- a/drivers/char/tpm/tpm-dev-common.c
+++ b/drivers/char/tpm/tpm-dev-common.c
@@ -61,6 +61,12 @@
 
 	mutex_lock(&priv->buffer_mutex);
 	priv->command_enqueued = false;
+	ret = tpm_try_get_ops(priv->chip);
+	if (ret) {
+		priv->response_length = ret;
+		goto out;
+	}
+
 	ret = tpm_dev_transmit(priv->chip, priv->space, priv->data_buffer,
 			       sizeof(priv->data_buffer));
 	tpm_put_ops(priv->chip);
@@ -68,6 +74,7 @@
 		priv->response_length = ret;
 		mod_timer(&priv->user_read_timer, jiffies + (120 * HZ));
 	}
+out:
 	mutex_unlock(&priv->buffer_mutex);
 	wake_up_interruptible(&priv->async_wait);
 }
@@ -123,7 +130,7 @@
 		priv->response_read = true;
 
 		ret_size = min_t(ssize_t, size, priv->response_length);
-		if (!ret_size) {
+		if (ret_size <= 0) {
 			priv->response_length = 0;
 			goto out;
 		}
@@ -182,15 +189,6 @@
 		goto out;
 	}
 
-	/* atomic tpm command send and result receive. We only hold the ops
-	 * lock during this period so that the tpm can be unregistered even if
-	 * the char dev is held open.
-	 */
-	if (tpm_try_get_ops(priv->chip)) {
-		ret = -EPIPE;
-		goto out;
-	}
-
 	priv->response_length = 0;
 	priv->response_read = false;
 	*off = 0;
@@ -208,6 +206,15 @@
 		return size;
 	}
 
+	/* atomic tpm command send and result receive. We only hold the ops
+	 * lock during this period so that the tpm can be unregistered even if
+	 * the char dev is held open.
+	 */
+	if (tpm_try_get_ops(priv->chip)) {
+		ret = -EPIPE;
+		goto out;
+	}
+
 	ret = tpm_dev_transmit(priv->chip, priv->space, priv->data_buffer,
 			       sizeof(priv->data_buffer));
 	tpm_put_ops(priv->chip);