Re: Soft lockup in rt2x00usb_work_rxdone()
On Wed, Nov 08, 2017 at 12:07:15PM +0100, Richard Genoud wrote: > (maybe if there was more than one CPU on the board, I could do > something, but that's not the case) I reproduced the problem with nosmp option. I think we need to check also for ENOENT error (not only for ENODEV). Will post the fix in a second. Thanks for reporting and debugging Stanislaw
Re: Soft lockup in rt2x00usb_work_rxdone()
On Wed, Nov 08, 2017 at 12:07:15PM +0100, Richard Genoud wrote:
> > No, that not I wanted you to do. Please remove those options and just
> > do
> > below on tracing directory.
> >
> > echo 0 > tracing_on
> > cat trace > /dev/null
> > echo "function_graph" > current_tracer
> > echo "rt2*" > set_ftrace_filter
> > echo 1 > tracing_on
> > echo 1-2.2 > /sys/bus/usb/drivers/usb/unbind
> > echo 0 > tracing_on
> > cat trace > ~/trace.txt
>
> Well, there's clearly a misunderstanding here :
> After the command "echo 1-2.2 > /sys/bus/usb/drivers/usb/unbind"
> I can't type *anything*
> The only thing I can do is plug off the board.
> This command never returns, so I can't stop the tracing...
>
> Or I missed something ?
>
> (maybe if there was more than one CPU on the board, I could do
> something, but that's not the case)
I was not aware that soft-lock up can hung the system.
Below patch should prevent/help with the issue. This is
not right fix, it's for futher debugging.
Regards
Stanislaw
diff --git a/drivers/net/wireless/ralink/rt2x00/rt2x00usb.c
b/drivers/net/wireless/ralink/rt2x00/rt2x00usb.c
index e2f4f5778267..d76ca608c722 100644
--- a/drivers/net/wireless/ralink/rt2x00/rt2x00usb.c
+++ b/drivers/net/wireless/ralink/rt2x00/rt2x00usb.c
@@ -321,8 +321,8 @@ static bool rt2x00usb_kick_tx_entry(struct queue_entry
*entry, void *data)
status = usb_submit_urb(entry_priv->urb, GFP_ATOMIC);
if (status) {
- if (status == -ENODEV)
- clear_bit(DEVICE_STATE_PRESENT, &rt2x00dev->flags);
+ printk("submit TX urb ERROR %d\n", status);
+ clear_bit(DEVICE_STATE_PRESENT, &rt2x00dev->flags);
set_bit(ENTRY_DATA_IO_FAILED, &entry->flags);
rt2x00lib_dmadone(entry);
}
@@ -410,8 +410,8 @@ static bool rt2x00usb_kick_rx_entry(struct queue_entry
*entry, void *data)
status = usb_submit_urb(entry_priv->urb, GFP_ATOMIC);
if (status) {
- if (status == -ENODEV)
- clear_bit(DEVICE_STATE_PRESENT, &rt2x00dev->flags);
+ printk("submit RX urb ERROR %d\n", status);
+ clear_bit(DEVICE_STATE_PRESENT, &rt2x00dev->flags);
set_bit(ENTRY_DATA_IO_FAILED, &entry->flags);
rt2x00lib_dmadone(entry);
}
Re: Soft lockup in rt2x00usb_work_rxdone()
Le mercredi 08 novembre 2017 à 11:37 +0100, Stanislaw Gruszka a écrit : > On Tue, Nov 07, 2017 at 12:01:23PM +0100, Richard Genoud wrote: > > Le mardi 07 novembre 2017 à 11:13 +0100, Stanislaw Gruszka a > > écrit : > > > On Tue, Nov 07, 2017 at 11:06:39AM +0100, Richard Genoud wrote: > > > > > 3 short articles how to configure and use ftrace are here: > > > > > https://lwn.net/Articles/365835/ > > > > > https://lwn.net/Articles/366796/ > > > > > https://lwn.net/Articles/370423/ > > > > > > > > > > > > > I tried with ftrace, but I don't think there's a way to dump > > > > the > > > > trace > > > > when there's a soft lock-up > > > > (I can't do anything after the unbind, even the heartbeat led > > > > stopped blinking). > > > > I saw the /proc/sys/kernel/ftrace_dump_on_oops file, but > > > > there's no > > > > /proc/sys/kernel/ftrace_dump_on_soft_lock-up file :) > > > > > > You should configure function trace with rt2x* functions. After > > > that > > > start tracing, unbind the device, then stop tracing and provide > > > trace > > > output. > > > > Ok, I found a way to display the trace (after the unbind, the board > > is > > frozen and I can't type anything). > > Adding > > CONFIG_SOFTLOCKUP_DETECTOR=y > > CONFIG_BOOTPARAM_SOFTLOCKUP_PANIC=y > > along with echo 1 > /proc/sys/kernel/ftrace_dump_on_oops does the > > trick > > No, that not I wanted you to do. Please remove those options and just > do > below on tracing directory. > > echo 0 > tracing_on > cat trace > /dev/null > echo "function_graph" > current_tracer > echo "rt2*" > set_ftrace_filter > echo 1 > tracing_on > echo 1-2.2 > /sys/bus/usb/drivers/usb/unbind > echo 0 > tracing_on > cat trace > ~/trace.txt Well, there's clearly a misunderstanding here : After the command "echo 1-2.2 > /sys/bus/usb/drivers/usb/unbind" I can't type *anything* The only thing I can do is plug off the board. This command never returns, so I can't stop the tracing... Or I missed something ? (maybe if there was more than one CPU on the board, I could do something, but that's not the case) > > and provide trace.txt to me (can be in private email if big). > > Thanks > Stanislaw Thanks, Richard.
Re: Soft lockup in rt2x00usb_work_rxdone()
On Tue, Nov 07, 2017 at 12:13:47PM +0100, Richard Genoud wrote:
> Le mardi 07 novembre 2017 à 11:13 +0100, Stanislaw Gruszka a écrit :
> > On Tue, Nov 07, 2017 at 11:06:39AM +0100, Richard Genoud wrote:
> > > > 3 short articles how to configure and use ftrace are here:
> > > > https://lwn.net/Articles/365835/
> > > > https://lwn.net/Articles/366796/
> > > > https://lwn.net/Articles/370423/
> > > >
> > >
> > > I tried with ftrace, but I don't think there's a way to dump the
> > > trace
> > > when there's a soft lock-up
> > > (I can't do anything after the unbind, even the heartbeat led
> > > stopped blinking).
> > > I saw the /proc/sys/kernel/ftrace_dump_on_oops file, but there's no
> > > /proc/sys/kernel/ftrace_dump_on_soft_lock-up file :)
> >
> > You should configure function trace with rt2x* functions. After that
> > start tracing, unbind the device, then stop tracing and provide trace
> > output.
> Here is another trace, with rt2* as function filter.
> (sorry for the noise)
>
> Dumping ftrace buffer:
> -
> CPU:0 [LOST 3606923 EVENTS]
> 0) 0.000 us| } /* rt2x00usb_clear_entry */
> 0) 0.000 us|} /* rt2x00lib_rxdone */
> 0) 0.000 us|rt2x00queue_get_entry();
> 0) |rt2x00lib_rxdone() {
> 0) 0.000 us| rt2x00queue_index_inc();
> 0) | rt2x00usb_clear_entry() {
> 0) |rt2x00usb_kick_rx_entry() {
We do that only if:
if (test_bit(DEVICE_STATE_PRESENT, &rt2x00dev->flags) &&
test_bit(DEVICE_STATE_ENABLED_RADIO, &rt2x00dev->flags))
rt2x00dev->ops->lib->clear_entry(entry);
so looks like DEVICE_STATE_PRESENT is not cleared. That mean
usb driver do not call disconnect callback on unbind. That seems
to be usb driver bug. Anyway please provide requested traces,
so I will see what happen.
Stanislaw
Re: Soft lockup in rt2x00usb_work_rxdone()
On Tue, Nov 07, 2017 at 12:01:23PM +0100, Richard Genoud wrote: > Le mardi 07 novembre 2017 à 11:13 +0100, Stanislaw Gruszka a écrit : > > On Tue, Nov 07, 2017 at 11:06:39AM +0100, Richard Genoud wrote: > > > > 3 short articles how to configure and use ftrace are here: > > > > https://lwn.net/Articles/365835/ > > > > https://lwn.net/Articles/366796/ > > > > https://lwn.net/Articles/370423/ > > > > > > > > > > I tried with ftrace, but I don't think there's a way to dump the > > > trace > > > when there's a soft lock-up > > > (I can't do anything after the unbind, even the heartbeat led > > > stopped blinking). > > > I saw the /proc/sys/kernel/ftrace_dump_on_oops file, but there's no > > > /proc/sys/kernel/ftrace_dump_on_soft_lock-up file :) > > > > You should configure function trace with rt2x* functions. After that > > start tracing, unbind the device, then stop tracing and provide trace > > output. > Ok, I found a way to display the trace (after the unbind, the board is > frozen and I can't type anything). > Adding > CONFIG_SOFTLOCKUP_DETECTOR=y > CONFIG_BOOTPARAM_SOFTLOCKUP_PANIC=y > along with echo 1 > /proc/sys/kernel/ftrace_dump_on_oops does the trick No, that not I wanted you to do. Please remove those options and just do below on tracing directory. echo 0 > tracing_on cat trace > /dev/null echo "function_graph" > current_tracer echo "rt2*" > set_ftrace_filter echo 1 > tracing_on echo 1-2.2 > /sys/bus/usb/drivers/usb/unbind echo 0 > tracing_on cat trace > ~/trace.txt and provide trace.txt to me (can be in private email if big). Thanks Stanislaw
Re: Soft lockup in rt2x00usb_work_rxdone()
Le mardi 07 novembre 2017 à 11:13 +0100, Stanislaw Gruszka a écrit :
> On Tue, Nov 07, 2017 at 11:06:39AM +0100, Richard Genoud wrote:
> > > 3 short articles how to configure and use ftrace are here:
> > > https://lwn.net/Articles/365835/
> > > https://lwn.net/Articles/366796/
> > > https://lwn.net/Articles/370423/
> > >
> >
> > I tried with ftrace, but I don't think there's a way to dump the
> > trace
> > when there's a soft lock-up
> > (I can't do anything after the unbind, even the heartbeat led
> > stopped blinking).
> > I saw the /proc/sys/kernel/ftrace_dump_on_oops file, but there's no
> > /proc/sys/kernel/ftrace_dump_on_soft_lock-up file :)
>
> You should configure function trace with rt2x* functions. After that
> start tracing, unbind the device, then stop tracing and provide trace
> output.
Here is another trace, with rt2* as function filter.
(sorry for the noise)
Dumping ftrace buffer:
-
CPU:0 [LOST 3606923 EVENTS]
0) 0.000 us| } /* rt2x00usb_clear_entry */
0) 0.000 us|} /* rt2x00lib_rxdone */
0) 0.000 us|rt2x00queue_get_entry();
0) |rt2x00lib_rxdone() {
0) 0.000 us| rt2x00queue_index_inc();
0) | rt2x00usb_clear_entry() {
0) |rt2x00usb_kick_rx_entry() {
0) | rt2x00lib_dmastart() {
0) 0.000 us|rt2x00queue_index_inc();
0) 0.000 us| }
0) | rt2x00lib_dmadone() {
0) 0.000 us|rt2x00queue_index_inc();
0) 0.000 us| }
0) 0.000 us|}
0) 0.000 us| }
0) 0.000 us|}
0) 0.000 us|rt2x00queue_get_entry();
0) |rt2x00lib_rxdone() {
0) 0.000 us| rt2x00queue_index_inc();
0) | rt2x00usb_clear_entry() {
0) |rt2x00usb_kick_rx_entry() {
0) | rt2x00lib_dmastart() {
0) 0.000 us|rt2x00queue_index_inc();
0) 0.000 us| }
0) | rt2x00lib_dmadone() {
0) 0.000 us|rt2x00queue_index_inc();
0) 0.000 us| }
0) 0.000 us|}
0) 0.000 us| }
0) 0.000 us|}
0) 0.000 us|rt2x00queue_get_entry();
0) |rt2x00lib_rxdone() {
0) 0.000 us| rt2x00queue_index_inc();
0) | rt2x00usb_clear_entry() {
0) |rt2x00usb_kick_rx_entry() {
0) | rt2x00lib_dmastart() {
0) 0.000 us|rt2x00queue_index_inc();
0) 0.000 us| }
0) | rt2x00lib_dmadone() {
0) 0.000 us|rt2x00queue_index_inc();
0) 0.000 us| }
0) 0.000 us|}
0) 0.000 us| }
0) 0.000 us|}
>
> Thanks
> Stanislaw
Re: Soft lockup in rt2x00usb_work_rxdone()
Le mardi 07 novembre 2017 à 11:13 +0100, Stanislaw Gruszka a écrit : > On Tue, Nov 07, 2017 at 11:06:39AM +0100, Richard Genoud wrote: > > > 3 short articles how to configure and use ftrace are here: > > > https://lwn.net/Articles/365835/ > > > https://lwn.net/Articles/366796/ > > > https://lwn.net/Articles/370423/ > > > > > > > I tried with ftrace, but I don't think there's a way to dump the > > trace > > when there's a soft lock-up > > (I can't do anything after the unbind, even the heartbeat led > > stopped blinking). > > I saw the /proc/sys/kernel/ftrace_dump_on_oops file, but there's no > > /proc/sys/kernel/ftrace_dump_on_soft_lock-up file :) > > You should configure function trace with rt2x* functions. After that > start tracing, unbind the device, then stop tracing and provide trace > output. Ok, I found a way to display the trace (after the unbind, the board is frozen and I can't type anything). Adding CONFIG_SOFTLOCKUP_DETECTOR=y CONFIG_BOOTPARAM_SOFTLOCKUP_PANIC=y along with echo 1 > /proc/sys/kernel/ftrace_dump_on_oops does the trick (trace is after the stack dump) # cd /sys/kernel/debug/tracing/ # echo 1 > /proc/sys/kernel/ftrace_dump_on_oops # # echo rt2x00usb* > set_ftrace_filter # echo 0 > tracing_on # echo function > current_tracer # echo 1 > tracing_on # echo 1-2.2 > /sys/bus/usb/drivers/usb/unbind [board frozen] watchdog: BUG: soft lockup - CPU#0 stuck for 22s! [kworker/u2:3:188] CPU: 0 PID: 188 Comm: kworker/u2:3 Not tainted 4.14.0-rc8-00040-g53fb1fe423ba #13 Hardware name: Atmel AT91SAM9 Workqueue: phy0 rt2x00usb_work_rxdone task: c7b34400 task.stack: c7b4e000 PC is at rb_commit+0x1a8/0x2e4 LR is at ring_buffer_unlock_commit+0x20/0xa4 pc : []lr : []psr: 8013 sp : c7b4fda8 ip : fp : c7b4fdc4 r10: c664ee34 r9 : c7b2ed18 r8 : 6013 r7 : 001c4851 r6 : c780a0e0 r5 : c7319340 r4 : 8a48 r3 : c7319340 r2 : c664e000 r1 : 0e38 r0 : 0e24 Flags: Nzcv IRQs on FIQs on Mode SVC_32 ISA ARM Segment none Control: 0005317f Table: 2727 DAC: 0053 CPU: 0 PID: 188 Comm: kworker/u2:3 Not tainted 4.14.0-rc8-00040-g53fb1fe423ba #13 Hardware name: Atmel AT91SAM9 Workqueue: phy0 rt2x00usb_work_rxdone [] (unwind_backtrace) from [] (show_stack+0x20/0x24) [] (show_stack) from [] (dump_stack+0x20/0x28) [] (dump_stack) from [] (show_regs+0x1c/0x20) [] (show_regs) from [] (watchdog_timer_fn+0x148/0x1ac) [] (watchdog_timer_fn) from [] (hrtimer_run_queues+0x128/0x250) [] (hrtimer_run_queues) from [] (run_local_timers+0x18/0x68) [] (run_local_timers) from [] (update_process_times+0x38/0x6c) [] (update_process_times) from [] (tick_nohz_handler+0xc0/0x10c) [] (tick_nohz_handler) from [] (ch2_irq+0x30/0x38) [] (ch2_irq) from [] (__handle_irq_event_percpu+0x74/0x1dc) [] (__handle_irq_event_percpu) from [] (handle_irq_event_percpu+0x2c/0x68) [] (handle_irq_event_percpu) from [] (handle_irq_event+0x38/0x4c) [] (handle_irq_event) from [] (handle_fasteoi_irq+0xa0/0x114) [] (handle_fasteoi_irq) from [] (generic_handle_irq+0x28/0x38) [] (generic_handle_irq) from [] (__handle_domain_irq+0x90/0xb8) [] (__handle_domain_irq) from [] (aic_handle+0xb0/0xb8) [] (aic_handle) from [] (__irq_svc+0x68/0x84) Exception stack(0xc7b4fd58 to 0xc7b4fda0) fd40: 0e24 0e38 fd60: c664e000 c7319340 8a48 c7319340 c780a0e0 001c4851 6013 c7b2ed18 fd80: c664ee34 c7b4fdc4 c7b4fda8 c006d724 c006c694 8013 [] (__irq_svc) from [] (rb_commit+0x1a8/0x2e4) [] (rb_commit) from [] (ring_buffer_unlock_commit+0x20/0xa4) [] (ring_buffer_unlock_commit) from [] (trace_function+0xe0/0xf0) [] (trace_function) from [] (function_trace_call+0xbc/0x11c) [] (function_trace_call) from [] (ftrace_graph_call+0x0/0xc) [] (ftrace_graph_call) from [] (rt2x00usb_kick_rx_entry+0x14/0x118) [] (rt2x00usb_kick_rx_entry) from [] (rt2x00usb_clear_entry+0x30/0x34) [] (rt2x00usb_clear_entry) from [] (rt2x00lib_rxdone+0x58c/0x5b8) [] (rt2x00lib_rxdone) from [] (rt2x00usb_work_rxdone+0x60/0x7c) [] (rt2x00usb_work_rxdone) from [] (process_one_work+0x1e4/0x3a0) [] (process_one_work) from [] (worker_thread+0x2c8/0x45c) [] (worker_thread) from [] (kthread+0x114/0x130) [] (kthread) from [] (ret_from_fork+0x14/0x2c) Kernel panic - not syncing: softlockup: hung tasks CPU: 0 PID: 188 Comm: kworker/u2:3 Tainted: G L 4.14.0-rc8-00040-g53fb1fe423ba #13 Hardware name: Atmel AT91SAM9 Workqueue: phy0 rt2x00usb_work_rxdone [] (unwind_backtrace) from [] (show_stack+0x20/0x24) [] (show_stack) from [] (dump_stack+0x20/0x28) [] (dump_stack) from [] (panic+0xc8/0x260) [] (panic) from [] (watchdog_timer_fn+0x180/0x1ac) [] (watchdog_timer_fn) from [] (hrtimer_run_queues+0x128/0x250) [] (hrtimer_run_queues) from [] (run_local_timers+0x18/0x68) [] (run_local_timers) from [] (update_process_times+0x38/0x6c) [] (update_process_times) from [] (tick_nohz_handler+0xc0/0x10c) [] (tick_nohz_handler) from [] (ch2_irq+0x30/0x38) [] (ch2_irq
Re: Soft lockup in rt2x00usb_work_rxdone()
On Tue, Nov 07, 2017 at 11:06:39AM +0100, Richard Genoud wrote: > > 3 short articles how to configure and use ftrace are here: > > https://lwn.net/Articles/365835/ > > https://lwn.net/Articles/366796/ > > https://lwn.net/Articles/370423/ > > > I tried with ftrace, but I don't think there's a way to dump the trace > when there's a soft lock-up > (I can't do anything after the unbind, even the heartbeat led stopped > blinking). > I saw the /proc/sys/kernel/ftrace_dump_on_oops file, but there's no > /proc/sys/kernel/ftrace_dump_on_soft_lock-up file :) You should configure function trace with rt2x* functions. After that start tracing, unbind the device, then stop tracing and provide trace output. Thanks Stanislaw
Re: Soft lockup in rt2x00usb_work_rxdone()
2017-11-07 9:53 GMT+01:00 Stanislaw Gruszka : > Hi Hi ! > > On Mon, Nov 06, 2017 at 04:57:09PM +0100, Richard Genoud wrote: >> I get a soft lock-up while unbinding the USB driver on a TP-Link TL-WN727Nv3 >> (chipset 5370): >> >> # echo 1-2.2 > /sys/bus/usb/drivers/usb/unbind >> watchdog: BUG: soft lockup - CPU#0 stuck for 23s! [kworker/u2:3:308] > ... >> I can trigger this each time. > > I can not reproduce this on my system (I'm using 4.14.0-rc6, but I don't > think it's an issue). I think the problem may be caused by usb > host controler driver, which can be different on your system. > > Does ftrace work on your platform ? If so could you use ftrace > to provide rt2x00 functions trace when the probllem happen ? > > 3 short articles how to configure and use ftrace are here: > https://lwn.net/Articles/365835/ > https://lwn.net/Articles/366796/ > https://lwn.net/Articles/370423/ > I tried with ftrace, but I don't think there's a way to dump the trace when there's a soft lock-up (I can't do anything after the unbind, even the heartbeat led stopped blinking). I saw the /proc/sys/kernel/ftrace_dump_on_oops file, but there's no /proc/sys/kernel/ftrace_dump_on_soft_lock-up file :) Or I missed something in ftrace ? Thanks ! Richard. > Thanks > Stanislaw
Re: Soft lockup in rt2x00usb_work_rxdone()
Hi On Mon, Nov 06, 2017 at 04:57:09PM +0100, Richard Genoud wrote: > I get a soft lock-up while unbinding the USB driver on a TP-Link TL-WN727Nv3 > (chipset 5370): > > # echo 1-2.2 > /sys/bus/usb/drivers/usb/unbind > watchdog: BUG: soft lockup - CPU#0 stuck for 23s! [kworker/u2:3:308] ... > I can trigger this each time. I can not reproduce this on my system (I'm using 4.14.0-rc6, but I don't think it's an issue). I think the problem may be caused by usb host controler driver, which can be different on your system. Does ftrace work on your platform ? If so could you use ftrace to provide rt2x00 functions trace when the probllem happen ? 3 short articles how to configure and use ftrace are here: https://lwn.net/Articles/365835/ https://lwn.net/Articles/366796/ https://lwn.net/Articles/370423/ Thanks Stanislaw
Soft lockup in rt2x00usb_work_rxdone()
Hi, I get a soft lock-up while unbinding the USB driver on a TP-Link TL-WN727Nv3 (chipset 5370): # echo 1-2.2 > /sys/bus/usb/drivers/usb/unbind watchdog: BUG: soft lockup - CPU#0 stuck for 23s! [kworker/u2:3:308] CPU: 0 PID: 308 Comm: kworker/u2:3 Not tainted 4.14.0-rc8 #11 Hardware name: Atmel AT91SAM9 Workqueue: phy0 rt2x00usb_work_rxdone task: c7b91000 task.stack: c7bee000 PC is at rt2x00lib_rxdone+0x590/0x5b8 LR is at rt2x00lib_dmadone+0x54/0x58 pc : []lr : []psr: 8013 sp : c7befebc ip : 0052 fp : c7befee4 r10: r9 : c79b2b58 r8 : r7 : c7816d00 r6 : c780e200 r5 : c79c68dc r4 : c7134ce0 r3 : 0001 r2 : c70bc200 r1 : a55f r0 : Flags: Nzcv IRQs on FIQs on Mode SVC_32 ISA ARM Segment none Control: 0005317f Table: 261b8000 DAC: 0053 CPU: 0 PID: 308 Comm: kworker/u2:3 Not tainted 4.14.0-rc8 #11 Hardware name: Atmel AT91SAM9 Workqueue: phy0 rt2x00usb_work_rxdone [] (unwind_backtrace) from [] (show_stack+0x20/0x24) [] (show_stack) from [] (dump_stack+0x20/0x28) [] (dump_stack) from [] (show_regs+0x1c/0x20) [] (show_regs) from [] (watchdog_timer_fn+0x148/0x1ac) [] (watchdog_timer_fn) from [] (hrtimer_run_queues+0x128/0x250) [] (hrtimer_run_queues) from [] (run_local_timers+0x18/0x68) [] (run_local_timers) from [] (update_process_times+0x38/0x6c) [] (update_process_times) from [] (tick_nohz_handler+0xc0/0x10c) [] (tick_nohz_handler) from [] (ch2_irq+0x30/0x38) [] (ch2_irq) from [] (__handle_irq_event_percpu+0x74/0x1dc) [] (__handle_irq_event_percpu) from [] (handle_irq_event_percpu+0x2c/0x68) [] (handle_irq_event_percpu) from [] (handle_irq_event+0x38/0x4c) [] (handle_irq_event) from [] (handle_fasteoi_irq+0xa0/0x114) [] (handle_fasteoi_irq) from [] (generic_handle_irq+0x28/0x38) [] (generic_handle_irq) from [] (__handle_domain_irq+0x90/0xb8) [] (__handle_domain_irq) from [] (aic_handle+0xb0/0xb8) [] (aic_handle) from [] (__irq_svc+0x68/0x84) Exception stack(0xc7befe68 to 0xc7befeb0) fe60: a55f c70bc200 0001 c7134ce0 c79c68dc fe80: c780e200 c7816d00 c79b2b58 c7befee4 0052 c7befebc fea0: c0331fdc c0332978 8013 [] (__irq_svc) from [] (rt2x00lib_rxdone+0x590/0x5b8) [] (rt2x00lib_rxdone) from [] (rt2x00usb_work_rxdone+0x60/0x7c) [] (rt2x00usb_work_rxdone) from [] (process_one_work+0x1e4/0x3a0) [] (process_one_work) from [] (worker_thread+0x2c8/0x45c) [] (worker_thread) from [] (kthread+0x114/0x130) [] (kthread) from [] (ret_from_fork+0x14/0x2c) I can trigger this each time. NB: if the wifi is deactivated properly before the unbind, there's no problem : # ifconfig wlan0 down ; echo 1-2.2 > /sys/bus/usb/drivers/usb/unbind wlan0: deauthenticating from 06:18:d6:91:9e:29 by local choice (Reason: 3=DEAUTH_LEAVING) Full dmesg: ## Booting kernel from Legacy Image at 20007fc0 ... Image Name: Linux-4.14.0-rc8 Image Type: ARM Linux Kernel Image (uncompressed) Data Size:4522192 Bytes = 4.3 MiB Load Address: 20008000 Entry Point: 20008000 ## Flattened Device Tree blob at 2640 Booting using the fdt blob at 0x2640 XIP Kernel Image ... OK Loading Device Tree to 27df2000, end 27dfcbb3 ... OK Starting kernel ... Booting Linux on physical CPU 0x0 Linux version 4.14.0-rc8 (rgenoud@lnx-rg) (gcc version 4.7.3 (GCC)) #11 Mon Nov 6 16:22:49 CET 2017 CPU: ARM926EJ-S [41069265] revision 5 (ARMv5TEJ), cr=0005317f CPU: VIVT data cache, VIVT instruction cache OF: fdt: Machine model: Paratronic LNS Memory policy: Data cache writeback On node 0 totalpages: 32768 free_area_init_node: node 0, pgdat c08a4b78, node_mem_map c7efb000 Normal zone: 256 pages used for memmap Normal zone: 0 pages reserved Normal zone: 32768 pages, LIFO batch:7 random: fast init done pcpu-alloc: s0 r0 d32768 u32768 alloc=1*32768 pcpu-alloc: [0] 0 Built 1 zonelists, mobility grouping on. Total pages: 32512 Kernel command line: loglevel=8 ro root=ubi0:rootfs rootfstype=ubifs ubi.mtd=ubi lpj=995328 ubi.fm_autoconvert=1 panic=2 mtdparts=atmel_nand:256M(all),128k@0(dtb),10112k(kernel),251392k(ubi),512k(bbt)ro atmel-nand-controller.use_dma=0 spidev.bufsiz=53200 video=320x240-32 PID hash table entries: 512 (order: -1, 2048 bytes) Dentry cache hash table entries: 16384 (order: 4, 65536 bytes) Inode-cache hash table entries: 8192 (order: 3, 32768 bytes) Memory: 120624K/131072K available (5847K kernel code, 475K rwdata, 1504K rodata, 480K init, 245K bss, 10448K reserved, 0K cma-reserved) Virtual kernel memory layout: vector : 0x - 0x1000 ( 4 kB) fixmap : 0xffc0 - 0xfff0 (3072 kB) vmalloc : 0xc880 - 0xff80 ( 880 MB) lowmem : 0xc000 - 0xc800 ( 128 MB) .text : 0xc0008000 - 0xc05be200 (5849 kB) .init : 0xc07be000 - 0xc0836000 ( 480 kB) .data : 0xc0836000 - 0xc08accd0 ( 476 kB) .bss : 0xc08b20e8 - 0xc08ef77c ( 246 kB) ftrace: allocating 23621 entries in 70 pages NR_IRQS: 16, nr_
