[PATCH 4.9 29/53] can: m_can: m_can_do_rx_poll(): fix extraneous msg loss warning

From: Greg Kroah-Hartman
Date: Mon Mar 29 2021 - 04:08:17 EST


From: Torin Cooper-Bennun <torin@xxxxxxxxxxxxxxxxxx>

[ 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@xxxxxxxxxxxxxxxxxx
Reported-by: Mariusz Madej <mariusz.madej@xxxxxxxxxx>
Signed-off-by: Torin Cooper-Bennun <torin@xxxxxxxxxxxxxxxxxx>
Signed-off-by: Marc Kleine-Budde <mkl@xxxxxxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
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