Re: kernel warning in usb_ep_queue() during suspend/resume

[Francesco Dolcini <francesco@dolcini.it>]

Hello Greg,

On Tue, Dec 12, 2023 at 05:44:43PM +0100, Greg Kroah-Hartman wrote:
> On Tue, Dec 12, 2023 at 05:36:14PM +0100, Francesco Dolcini wrote:
> >   ------------[ cut here ]------------
> >   WARNING: CPU: 0 PID: 1385 at drivers/usb/gadget/udc/core.c:295 usb_ep_queue+0x58/0x6c
> >   Modules linked in: 8021q bnep mcp251x mwifiex_sdio mwifiex cfg80211 btmrvl_sdio btmrvl imx_sdma fuse
> >   CPU: 0 PID: 1385 Comm: analogclock Not tainted 6.1.66-6.5.0-devel+git.6c6a6c7e211c #1
> >   Hardware name: Freescale i.MX6 Ultralite (Device Tree)
> >    unwind_backtrace from show_stack+0x10/0x14
> >    show_stack from dump_stack_lvl+0x40/0x4c
> >    dump_stack_lvl from __warn+0x88/0xc0
> >    __warn from warn_slowpath_fmt+0x10c/0x1a0
> >    warn_slowpath_fmt from usb_ep_queue+0x58/0x6c
> >    usb_ep_queue from eth_start_xmit+0x1ec/0x330
> >    eth_start_xmit from dev_hard_start_xmit+0x7c/0xf8
> >    dev_hard_start_xmit from sch_direct_xmit+0x110/0x310
> >    sch_direct_xmit from __qdisc_run+0x110/0x5d8
> >    __qdisc_run from net_tx_action+0x170/0x20c
> >    net_tx_action from __do_softirq+0xc0/0x234
> >    __do_softirq from __irq_exit_rcu+0x8c/0xb8
> >    __irq_exit_rcu from irq_exit+0x8/0x10
> >    irq_exit from call_with_stack+0x18/0x20
> >    call_with_stack from __irq_usr+0x7c/0xa0
> >   Exception stack(0xe0fcdfb0 to 0xe0fcdff8)
> >   dfa0:                                     b2f9e000 b30775a0 0002edf8 00000000
> >   dfc0: 01493268 014fdd00 0002edf8 0002edf8 000185b8 be8d9734 b3f6f811 0000000c
> >   dfe0: b2fb4580 be8d95f4 b3f6f7d3 b64006a8 20070010 ffffffff
> >   ---[ end trace 0000000000000000 ]---
> > 
> > 
> > The warning is happening during a suspend/resume test (not sure which
> > one of the twos), I cannot really tell if this is a regression (and from
> > which version, eventually), but this is happening since a while with
> > multiple 6.1 kernel version (this last log is from a recent 6.1.66).
> > 
> > I cannot really tell the current status with mainline or v6.6 given that
> > it does not seems so trivial to reproduce.
> > 
> > It happened on various arm and arm64 machine.
> 
> After the warning happens, does the machine still work?
yes, the machine keeps working. I cannot tell much more since this is
happening sporadically while doing some automated test and a few seconds
after it is just switched off.


Thanks,
Francesco