diff options
| author | Markus Pargmann <mpa@pengutronix.de> | 2013-10-28 09:54:40 +0100 |
|---|---|---|
| committer | Marc Kleine-Budde <mkl@pengutronix.de> | 2013-10-31 20:18:47 +0100 |
| commit | 5d0f801a2ccec3b1fdabc3392c8d99ed0413d216 (patch) | |
| tree | 1f14267633c2f77bba89877beb51fc9db49c3058 /drivers | |
| parent | c17cb8b55b104c549aa20a72fa44141ad2c65ec2 (diff) | |
| download | lwn-5d0f801a2ccec3b1fdabc3392c8d99ed0413d216.tar.gz lwn-5d0f801a2ccec3b1fdabc3392c8d99ed0413d216.zip | |
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: Markus Pargmann <mpa@pengutronix.de>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
Diffstat (limited to 'drivers')
| -rw-r--r-- | drivers/net/can/c_can/c_can.c | 6 |
1 files 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 a668cd491cb3..e3fc07cf2f62 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; |