Cc'ing more people.
On 6/24/19 8:01 PM, Guenter Roeck wrote:
> Hi,
>
> I have seen the following problem several times recently. This is with
> qemu-4.0.
>
> qemu-system-x86_64: hw/usb/core.c:720: usb_ep_get: Assertion `dev != NULL'
> failed
>
> Backtrace gives me the following call path.
>
> main_loop()
> main_loop_wait()
> glib_pollfds_poll()
> aio_ctx_dispatch()
> aio_dispatch()
> aio_bh_poll()
> ehci_work_bh()
> ehci_advance_async_state()
> ehci_advance_state()
> ehci_execute()
> usb_ep_get()
>
> The problem always happens during shutdown, maybe once every 100 boots.
> It seems to be more likely to happen when the system is under heavy load.
>
> ...
> umount: devtmpfs busy - remounted read-only
> [ 49.018682] EXT4-fs (sda): re-mounted. Opts: (null)
> [ 49.028052] sd 6:0:0:0: [sda] Synchronizing SCSI cache
> qemu-system-x86_64: hw/usb/core.c:733: usb_ep_get: Assertion `dev != NULL'
> failed.
>
> Essentially that means that p->queue->dev is NULL in ehci_execute().
>
> Has anyone else seen this problem ? Any idea what I can do to debug
> this further ?
>
> Thanks,
> Guenter
>
