MUSB interrupt storm on device removal

["Måns Rullgård" <mans@mansr.com>]

Bin Liu <b-liu@ti.com> writes:

> On Mon, Jan 21, 2019 at 09:20:52PM +0000, Måns Rullgård wrote:
>> Bin Liu <b-liu@ti.com> writes:
>> 
>> > On Fri, Jan 18, 2019 at 08:15:02PM +0000, Måns Rullgård wrote:
>> >> Bin Liu <b-liu@ti.com> writes:
>> >> 
>> >> > On Mon, Dec 17, 2018 at 09:36:17PM +0000, Måns Rullgård wrote:
>> >> >> Bin Liu <b-liu@ti.com> writes:
>> >> >> 
>> >> >> > On Mon, Dec 17, 2018 at 07:16:08PM +0000, Måns Rullgård wrote:
>> >> >> >> Bin Liu <b-liu@ti.com> writes:
>> >> >> >> 
>> >> >> >> > Hi,
>> >> >> >> >
>> >> >> >> > On Mon, Dec 17, 2018 at 03:13:12PM +0000, Måns Rullgård wrote:
>> >> >> >> >> I have a strange problem with the musb driver in host mode on AM3358
>> >> >> >> >> (beaglebone) hardware.  If I connect a multi-port serial adapter and
>> >
>> > Is this on beaglebone or beagleboneblack?
>> 
>> We've seen it with Beaglebone Enhanced [1] and BeagleCore [2] based
>> devices.  Both are based on the AM3358 and mostly compatible with the
>> Beaglebone Black.
>> 
>> [1] https://elinux.org/SanCloud_BeagleBoneEnhanced
>> [2] http://beaglecore.com/products/bcm1str.html
>
> Okay, now I see you have a hub on the board. I just reproduced the
> console lockup after added a hub in my setup. I will find some time to
> debug this.
>
> FYI, there was a similar issue in a few years ago, which was that the
> hub routine never got called during the storm then the device disconnect
> event never got populated from the hub driver. I am wondering if this is
> the same issue pops up again...

Now that you mentioned the hub, I tried connecting the serial adapter to
the OTG port (in host mode) on the Beaglebone Enhanced (it's not
normally used in this product).  When connected directly, the disconnect
indeed works properly.  With a hub in between, it breaks.