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From: Dario Binacchi <dariobin@libero.it>
To: linux-kernel@vger.kernel.org
Cc: Gianluca Falavigna <gianluca.falavigna@inwind.it>,
	Dario Binacchi <dariobin@libero.it>,
	"David S. Miller" <davem@davemloft.net>,
	Jakub Kicinski <kuba@kernel.org>,
	Marc Kleine-Budde <mkl@pengutronix.de>,
	Oliver Hartkopp <socketcan@hartkopp.net>,
	Vincent Mailhol <mailhol.vincent@wanadoo.fr>,
	Wolfgang Grandegger <wg@grandegger.com>,
	linux-can@vger.kernel.org, netdev@vger.kernel.org
Subject: [PATCH 2/4] can: c_can: exit c_can_do_tx() early if no frames have been sent
Date: Fri, 16 Jul 2021 18:56:21 +0200	[thread overview]
Message-ID: <20210716165623.19677-3-dariobin@libero.it> (raw)
In-Reply-To: <20210716165623.19677-1-dariobin@libero.it>

The c_can_poll() handles RX/TX events unconditionally. It may therefore
happen that c_can_do_tx() is called unnecessarily because the interrupt
was triggered by the reception of a frame. In these cases, we avoid to
execute unnecessary statements and exit immediately.

Signed-off-by: Dario Binacchi <dariobin@libero.it>
---

 drivers/net/can/c_can/c_can_main.c | 11 ++++++-----
 1 file changed, 6 insertions(+), 5 deletions(-)

diff --git a/drivers/net/can/c_can/c_can_main.c b/drivers/net/can/c_can/c_can_main.c
index 7588f70ca0fe..fec0e3416970 100644
--- a/drivers/net/can/c_can/c_can_main.c
+++ b/drivers/net/can/c_can/c_can_main.c
@@ -720,17 +720,18 @@ static void c_can_do_tx(struct net_device *dev)
 		pkts++;
 	}
 
+	if (!pkts)
+		return;
+
 	/* Clear the bits in the tx_active mask */
 	atomic_sub(clr, &priv->tx_active);
 
 	if (clr & BIT(priv->msg_obj_tx_num - 1))
 		netif_wake_queue(dev);
 
-	if (pkts) {
-		stats->tx_bytes += bytes;
-		stats->tx_packets += pkts;
-		can_led_event(dev, CAN_LED_EVENT_TX);
-	}
+	stats->tx_bytes += bytes;
+	stats->tx_packets += pkts;
+	can_led_event(dev, CAN_LED_EVENT_TX);
 }
 
 /* If we have a gap in the pending bits, that means we either
-- 
2.17.1


  parent reply	other threads:[~2021-07-16 16:57 UTC|newest]

Thread overview: 5+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-07-16 16:56 [PATCH 0/4] can: c_can: cache frames to operate as a true FIFO Dario Binacchi
2021-07-16 16:56 ` [PATCH 1/4] can: c_can: remove struct c_can_priv::priv field Dario Binacchi
2021-07-16 16:56 ` Dario Binacchi [this message]
2021-07-16 16:56 ` [PATCH 3/4] can: c_can: support tx ring algorithm Dario Binacchi
2021-07-16 16:56 ` [PATCH 4/4] can: c_can: cache frames to operate as a true FIFO Dario Binacchi

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