netdev - [net-next 36/39] can: c_can: add a comment about IF

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Message-Id: <20210330114559.1114855-37-mkl@pengutronix.de>
Date:   Tue, 30 Mar 2021 13:45:56 +0200
From:   Marc Kleine-Budde <mkl@...gutronix.de>
To:     netdev@...r.kernel.org
Cc:     davem@...emloft.net, kuba@...nel.org, linux-can@...r.kernel.org,
        kernel@...gutronix.de, Dario Binacchi <dariobin@...ero.it>,
        Marc Kleine-Budde <mkl@...gutronix.de>
Subject: [net-next 36/39] can: c_can: add a comment about IF_RX interface's use

From: Dario Binacchi <dariobin@...ero.it>

After reading the commit 640916db2bf7 ("can: c_can: Make it SMP safe")
it may sound strange to see the IF_RX interface used by the
can_inval_tx_object function. A comment was added to avoid any
misunderstanding.

Link: https://lore.kernel.org/r/20210302215435.18286-4-dariobin@libero.it
Signed-off-by: Dario Binacchi <dariobin@...ero.it>
Signed-off-by: Marc Kleine-Budde <mkl@...gutronix.de>
---
 drivers/net/can/c_can/c_can.c | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/drivers/net/can/c_can/c_can.c b/drivers/net/can/c_can/c_can.c
index 8212f3d98aa9..980abf6a8609 100644
--- a/drivers/net/can/c_can/c_can.c
+++ b/drivers/net/can/c_can/c_can.c
@@ -710,6 +710,11 @@ static void c_can_do_tx(struct net_device *dev)
 		idx--;
 		pend &= ~(1 << idx);
 		obj = idx + C_CAN_MSG_OBJ_TX_FIRST;
+
+		/* We use IF_RX interface instead of IF_TX because we
+		 * are called from c_can_poll(), which runs inside
+		 * NAPI. We are not trasmitting.
+		 */
 		c_can_inval_tx_object(dev, IF_RX, obj);
 		can_get_echo_skb(dev, idx, NULL);
 		bytes += priv->dlc[idx];
-- 
2.30.2