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Subject[PATCH] can: c_can: Handle lost message before EOB
Date
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 a interrupt
loop.

This patch handles lost packets before EOB packets.

Signed-off-by: Markus Pargmann <mpa@pengutronix.de>
---
drivers/net/can/c_can/c_can.c | 6 +++---
1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/drivers/net/can/c_can/c_can.c b/drivers/net/can/c_can/c_can.c
index a668cd4..e3fc07c 100644
--- a/drivers/net/can/c_can/c_can.c
+++ b/drivers/net/can/c_can/c_can.c
@@ -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;

--
1.8.4.rc3


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