mirror of
https://github.com/openwrt/openwrt.git
synced 2024-12-23 07:22:33 +00:00
63 lines
2.5 KiB
Diff
63 lines
2.5 KiB
Diff
|
From 59876225748221d7ebbdb9c892a2086420ddd80d Mon Sep 17 00:00:00 2001
|
||
|
|
From: Sean Nyekjaer <sean@geanix.com>
|
||
|
|
Date: Thu, 14 Nov 2019 19:56:28 +0800
|
||
|
|
Subject: [PATCH] can: flexcan: fix deadlock when using self wakeup
|
||
|
|
|
||
|
|
When suspending, when there is still can traffic on the interfaces the
|
||
|
|
flexcan immediately wakes the platform again. As it should :-). But it
|
||
|
|
throws this error msg:
|
||
|
|
[ 3169.378661] PM: noirq suspend of devices failed
|
||
|
|
|
||
|
|
On the way down to suspend the interface that throws the error message does
|
||
|
|
call flexcan_suspend but fails to call flexcan_noirq_suspend. That means the
|
||
|
|
flexcan_enter_stop_mode is called, but on the way out of suspend the driver
|
||
|
|
only calls flexcan_resume and skips flexcan_noirq_resume, thus it doesn't call
|
||
|
|
flexcan_exit_stop_mode. This leaves the flexcan in stop mode, and with the
|
||
|
|
current driver it can't recover from this even with a soft reboot, it requires
|
||
|
|
a hard reboot.
|
||
|
|
|
||
|
|
This patch can fix deadlock when using self wakeup, it happenes to be
|
||
|
|
able to fix another issue that frames out-of-order in first IRQ handler
|
||
|
|
run after wakeup.
|
||
|
|
|
||
|
|
In wakeup case, after system resume, frames received out-of-order,the
|
||
|
|
problem is wakeup latency from frame reception to IRQ handler is much
|
||
|
|
bigger than the counter overflow. This means it's impossible to sort the
|
||
|
|
CAN frames by timestamp. The reason is that controller exits stop mode
|
||
|
|
during noirq resume, then it can receive the frame immediately. If
|
||
|
|
noirq reusme stage consumes much time, it will extend interrupt response
|
||
|
|
time.
|
||
|
|
|
||
|
|
Fixes: de3578c198c6 ("can: flexcan: add self wakeup support")
|
||
|
|
Signed-off-by: Sean Nyekjaer <sean@geanix.com>
|
||
|
|
Signed-off-by: Joakim Zhang <qiangqing.zhang@nxp.com>
|
||
|
|
---
|
||
|
|
drivers/net/can/flexcan.c | 9 +++++++--
|
||
|
|
1 file changed, 7 insertions(+), 2 deletions(-)
|
||
|
|
|
||
|
|
--- a/drivers/net/can/flexcan.c
|
||
|
|
+++ b/drivers/net/can/flexcan.c
|
||
|
|
@@ -137,8 +137,7 @@
|
||
|
|
(FLEXCAN_ESR_ERR_BUS | FLEXCAN_ESR_ERR_STATE)
|
||
|
|
#define FLEXCAN_ESR_ALL_INT \
|
||
|
|
(FLEXCAN_ESR_TWRN_INT | FLEXCAN_ESR_RWRN_INT | \
|
||
|
|
- FLEXCAN_ESR_BOFF_INT | FLEXCAN_ESR_ERR_INT | \
|
||
|
|
- FLEXCAN_ESR_WAK_INT)
|
||
|
|
+ FLEXCAN_ESR_BOFF_INT | FLEXCAN_ESR_ERR_INT)
|
||
|
|
|
||
|
|
/* FLEXCAN Bit Timing register (CBT) bits */
|
||
|
|
#define FLEXCAN_CBT_BTF BIT(31)
|
||
|
|
@@ -1055,6 +1054,12 @@ static irqreturn_t flexcan_irq(int irq,
|
||
|
|
|
||
|
|
reg_esr = priv->read(®s->esr);
|
||
|
|
|
||
|
|
+ /* ACK wakeup interrupt */
|
||
|
|
+ if (reg_esr & FLEXCAN_ESR_WAK_INT) {
|
||
|
|
+ handled = IRQ_HANDLED;
|
||
|
|
+ priv->write(reg_esr & FLEXCAN_ESR_WAK_INT, ®s->esr);
|
||
|
|
+ }
|
||
|
|
+
|
||
|
|
/* ACK all bus error and state change IRQ sources */
|
||
|
|
if (reg_esr & FLEXCAN_ESR_ALL_INT) {
|
||
|
|
handled = IRQ_HANDLED;
|