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Commit 5d0f801a authored by Markus Pargmann's avatar Markus Pargmann Committed by Marc Kleine-Budde
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can: c_can: Fix RX message handling, handle lost message before EOB 



If we handle end of block messages with higher priority than a lost message,
we can run into an endless interrupt loop.

This is reproducable with a am335x processor and "cansequence -r" at 1Mbit.
As soon as we loose a packet we can't escape from an interrupt loop.

This patch fixes the problem by handling lost packets before EOB packets.

Cc: linux-stable <stable@vger.kernel.org>
Signed-off-by: default avatarMarkus Pargmann <mpa@pengutronix.de>
Signed-off-by: default avatarMarc Kleine-Budde <mkl@pengutronix.de>
parent c17cb8b5

drivers/net/can/c_can/c_can.c

+3 −3
Original line number Diff line number Diff line
@@ -814,9 +814,6 @@ static int c_can_do_rx_poll(struct net_device *dev, int quota) 
			msg_ctrl_save = priv->read_reg(priv,

					C_CAN_IFACE(MSGCTRL_REG, 0));



			if (msg_ctrl_save & IF_MCONT_EOB)

				return num_rx_pkts;



			if (msg_ctrl_save & IF_MCONT_MSGLST) {

				c_can_handle_lost_msg_obj(dev, 0, msg_obj);

				num_rx_pkts++;
@@ -824,6 +821,9 @@ static int c_can_do_rx_poll(struct net_device *dev, int quota) 
				continue;

			}



			if (msg_ctrl_save & IF_MCONT_EOB)

				return num_rx_pkts;



			if (!(msg_ctrl_save & IF_MCONT_NEWDAT))

				continue;