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From: Torin Cooper-Bennun <torin@maxiluxsystems.com>
To: Mariusz Madej <mariusz.madej@xtrack.com>
Cc: "linux-can@vger.kernel.org" <linux-can@vger.kernel.org>,
	Wolfgang Grandegger <wg@grandegger.com>,
	Marc Kleine-Budde <mkl@pengutronix.de>
Subject: Re: [PATCH] can: m_can: reset IR_RF0L in message reception loop
Date: Wed, 3 Mar 2021 08:08:09 +0000	[thread overview]
Message-ID: <20210303080809.zfjh6oolqxcv4pir@bigthink> (raw)
In-Reply-To: <0710fbd2-4b88-21bf-88f7-0b97d7e7dc0b@xtrack.com>

On Mon, Mar 01, 2021 at 10:21:27PM +0100, Mariusz Madej wrote:
> Message lost warning is reported in loop without interrupt reset. Besides
> redundant log messages it may lead to serious performance problem, where
> fifo gets full faster than next reception is scheduled by NAPI. This
> patch fixes it.

Looking at the flow in m_can_rx_handler, it looks as though
m_can_handle_bus_errors -> m_can_handle_lost_msg already handles message
loss properly, and issues a netdev_err. I wonder whether we can remove
the warning from m_can_do_rx_poll entirely:

diff --git a/drivers/net/can/m_can/m_can.c b/drivers/net/can/m_can/m_can.c
index 3752520a7d4b..d783c46cac16 100644
--- a/drivers/net/can/m_can/m_can.c
+++ b/drivers/net/can/m_can/m_can.c
@@ -501,9 +501,6 @@ static int m_can_do_rx_poll(struct net_device *dev, int quota)
 	}
 
 	while ((rxfs & RXFS_FFL_MASK) && (quota > 0)) {
-		if (rxfs & RXFS_RFL)
-			netdev_warn(dev, "Rx FIFO 0 Message Lost\n");
-
 		m_can_read_fifo(dev, rxfs);
 
 		quota--;

---
Regards,

Torin Cooper-Bennun
Software Engineer | maxiluxsystems.com


  reply	other threads:[~2021-03-04  0:23 UTC|newest]

Thread overview: 4+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-03-01 21:21 [PATCH] can: m_can: reset IR_RF0L in message reception loop Mariusz Madej
2021-03-03  8:08 ` Torin Cooper-Bennun [this message]
2021-03-03  8:31   ` Marc Kleine-Budde
2021-03-03 10:20     ` Torin Cooper-Bennun

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