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 <[email protected]> Signed-off-by: Markus Pargmann <[email protected]> Signed-off-by: Marc Kleine-Budde <[email protected]>
levisjani · Oct 31, 2013 · 5d0f801 · 5d0f801
1 parent c17cb8b
commit 5d0f801
Showing 1 changed file with 3 additions and 3 deletions.
diff --git a/drivers/net/can/c_can/c_can.c b/drivers/net/can/c_can/c_can.c
@@ -814,16 +814,16 @@ 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++;
 				quota--;
 				continue;
 			}
 
+			if (msg_ctrl_save & IF_MCONT_EOB)
+				return num_rx_pkts;
+
 			if (!(msg_ctrl_save & IF_MCONT_NEWDAT))
 				continue;