linux-kernel - [PATCH 4.4 26/33] can: m_can: m_can_do_rx_poll(): fix extraneous msg loss warning

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Date:   Mon, 29 Mar 2021 09:58:11 +0200
From:   Greg Kroah-Hartman <gregkh@...uxfoundation.org>
To:     linux-kernel@...r.kernel.org
Cc:     Greg Kroah-Hartman <gregkh@...uxfoundation.org>,
        stable@...r.kernel.org, Mariusz Madej <mariusz.madej@...ack.com>,
        Torin Cooper-Bennun <torin@...iluxsystems.com>,
        Marc Kleine-Budde <mkl@...gutronix.de>,
        Sasha Levin <sashal@...nel.org>
Subject: [PATCH 4.4 26/33] can: m_can: m_can_do_rx_poll(): fix extraneous msg loss warning

From: Torin Cooper-Bennun <torin@...iluxsystems.com>

[ Upstream commit c0e399f3baf42279f48991554240af8c457535d1 ]

Message loss from RX FIFO 0 is already handled in
m_can_handle_lost_msg(), with netdev output included.

Removing this warning also improves driver performance under heavy
load, where m_can_do_rx_poll() may be called many times before this
interrupt is cleared, causing this message to be output many
times (thanks Mariusz Madej for this report).

Fixes: e0d1f4816f2a ("can: m_can: add Bosch M_CAN controller support")
Link: https://lore.kernel.org/r/20210303103151.3760532-1-torin@maxiluxsystems.com
Reported-by: Mariusz Madej <mariusz.madej@...ack.com>
Signed-off-by: Torin Cooper-Bennun <torin@...iluxsystems.com>
Signed-off-by: Marc Kleine-Budde <mkl@...gutronix.de>
Signed-off-by: Sasha Levin <sashal@...nel.org>
---
 drivers/net/can/m_can/m_can.c | 3 ---
 1 file changed, 3 deletions(-)

diff --git a/drivers/net/can/m_can/m_can.c b/drivers/net/can/m_can/m_can.c
index 0bd7e7164796..197c27d8f584 100644
--- a/drivers/net/can/m_can/m_can.c
+++ b/drivers/net/can/m_can/m_can.c
@@ -428,9 +428,6 @@ 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--;
-- 
2.30.1