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| author | Markus Pargmann <mpa@pengutronix.de> | 2013-10-28 09:54:40 +0100 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2013-11-29 10:42:15 -0800 |
| commit | 9a371e60e72b0e7b0e644f0db3e0ed358b592529 (patch) | |
| tree | 9e5c389f0f7f44e990ce749b9b402cffd3af00ab | |
| parent | 3a43b09c33d957866adfe6afaff102a6820ef610 (diff) | |
| download | lwn-9a371e60e72b0e7b0e644f0db3e0ed358b592529.tar.gz lwn-9a371e60e72b0e7b0e644f0db3e0ed358b592529.zip | |
can: c_can: Fix RX message handling, handle lost message before EOB
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>
| -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; |