From: Li RongQing <roy.qing.li@xxxxxxxxx>
force to stop the watchdog when unregister, otherwise the watchdog maybe
be suspended and be run after the module is unloaded, like the below:
$modprobe softdog
$echo 1 >/dev/watchdog
$modprobe -r softdog
CPU 20 Unable to handle kernel paging request at virtual address
Oops[#1]:
CPU: 20 PID: 0 Comm: swapper/20 Not tainted 4.1.13-WR8.0.0.0_standard #6
...
Modules linked in: [last unloaded: softdog]
....
Call Trace:
[<ffffffff801e142c>] cascade+0x34/0xb0
[<ffffffff801e1964>] run_timer_softirq+0x30c/0x368
[<ffffffff80181044>] __do_softirq+0x1ec/0x418
[<ffffffff801815d0>] irq_exit+0x90/0x98
[<ffffffff8010749c>] plat_irq_dispatch+0xa4/0x140
[<ffffffff80152740>] ret_from_irq+0x0/0x4
[<ffffffff801529e0>] __r4k_wait+0x20/0x40
[<ffffffff801c2278>] cpu_startup_entry+0x2a0/0x368
[<ffffffff8015fa64>] start_secondary+0x444/0x4d8
Signed-off-by: Li RongQing <roy.qing.li@xxxxxxxxx>
---
drivers/watchdog/watchdog_dev.c | 2 ++
1 file changed, 2 insertions(+)
diff --git a/drivers/watchdog/watchdog_dev.c b/drivers/watchdog/watchdog_dev.c
index 56a649e..2f3139b 100644
--- a/drivers/watchdog/watchdog_dev.c
+++ b/drivers/watchdog/watchdog_dev.c
@@ -569,6 +569,8 @@ int watchdog_dev_register(struct watchdog_device *wdd)
int watchdog_dev_unregister(struct watchdog_device *wdd)
{
+ watchdog_stop(wdd);
+
mutex_lock(&wdd->lock);
set_bit(WDOG_UNREGISTERED, &wdd->status);
mutex_unlock(&wdd->lock);
--
2.1.4
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