| From 5d0f801a2ccec3b1fdabc3392c8d99ed0413d216 Mon Sep 17 00:00:00 2001 |
| From: Markus Pargmann <mpa@pengutronix.de> |
| Date: Mon, 28 Oct 2013 09:54:40 +0100 |
| Subject: can: c_can: Fix RX message handling, handle lost message before EOB |
| |
| From: Markus Pargmann <mpa@pengutronix.de> |
| |
| commit 5d0f801a2ccec3b1fdabc3392c8d99ed0413d216 upstream. |
| |
| 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. |
| |
| Signed-off-by: Markus Pargmann <mpa@pengutronix.de> |
| Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de> |
| Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> |
| |
| --- |
| drivers/net/can/c_can/c_can.c | 6 +++--- |
| 1 file changed, 3 insertions(+), 3 deletions(-) |
| |
| --- 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_d |
| 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_d |
| continue; |
| } |
| |
| + if (msg_ctrl_save & IF_MCONT_EOB) |
| + return num_rx_pkts; |
| + |
| if (!(msg_ctrl_save & IF_MCONT_NEWDAT)) |
| continue; |
| |
