This is a note to let you know that I've just added the patch titled
can: c_can: Fix RX message handling, handle lost message before EOB
to the 3.4-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
can-c_can-fix-rx-message-handling-handle-lost-message-before-eob.patch
and it can be found in the queue-3.4 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
>From 5d0f801a2ccec3b1fdabc3392c8d99ed0413d216 Mon Sep 17 00:00:00 2001
From: Markus Pargmann <mpa@xxxxxxxxxxxxxx>
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@xxxxxxxxxxxxxx>
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@xxxxxxxxxxxxxx>
Signed-off-by: Marc Kleine-Budde <mkl@xxxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
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
@@ -760,9 +760,6 @@ static int c_can_do_rx_poll(struct net_d
msg_ctrl_save = priv->read_reg(priv,
&priv->regs->ifregs[0].msg_cntrl);
- 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++;
@@ -770,6 +767,9 @@ 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;
Patches currently in stable-queue which might be from mpa@xxxxxxxxxxxxxx are
queue-3.4/can-c_can-fix-rx-message-handling-handle-lost-message-before-eob.patch
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