Re: removing certain umass (cd/dvd?) devices appears to lock up the USB bus on 14.2/14.3 (at least)

Hey David,

Did you get a chance to try the USB sticks with -current yet?

Warner

On Thu, Aug 7, 2025 at 12:54 PM Warner Losh <imp@bsdimp.com> wrote:

> Maybe you could try 15.0. I've done a lot to fix these things in 15.0.
> If it still happens there, we'll talk about changes. I've not MFC'd
> the changes I've made since they are kinda extensive. On the other
> hand, there's been a lot of reports of 'works better for me' with only
> one regression. On the other hand, it's not entirely clear this is in
> the class of problems I solved.
>
> Sadly, I suspect that we'll need to have hardware in the right hands
> to solve this completely, especially since the reproduction appears to
> be hit or miss. Is this a pure DVD drive? Is it portable or desktop?
> If it's the one I found on ebay (https://www.ebay.com/itm/396752411077
> though there's others), looks in budget for me to obtain to help if
> there's a reliable recipe to reproduce and it's not the "fault" of
> your host USB chipset.
>
> Warner
>
> On Thu, Aug 7, 2025 at 12:43 PM David Cross <david@crossfamilyweb.com>
> wrote:
> >
> > I have a USB DVD drive that when I unplug (even when empty and
> > unmounted) appears to stop the entire USB stack on 14.2/14.3. There are
> > no errors (that I can see) in the dmesg, it *appears* to detach, but
> > then no other USB events happen.
> >
> >
> > I originally thought it was just the port that it was attached to, but
> > in recent experimentation I attached it to a USB hub, then detached it
> > from the hub, and even other ports on the host stopped responding.
> > Currently connected devices appear to continue to work, but if removed
> > nothing will reattach to those ports.
> >
> >
> > This has now happened across a couple of different machines with this
> > device, so I don't think it is host specific behavior
> >
> >
> > When trying to run 'usbconfig -v - l' to get some kind of diagnostics it
> > just hangs; C-t yields the following:
> >
> >
> >  > load: 0.12  cmd: usbconfig 52496 [USB config SX lock] 3.12r 0.00u
> > 0.00s 0% 2280k
> >
> >
> > Of course in the interests of a fresh reproduction for this email, it
> > just worked; I am continuing to attempt to reproduce. Suggestions of
> > things I should try when I am successful to diagnose the issue so we can
> > fix it?
> >
> > The relevant USB attach messages are:
> >
> > ugen1.10: <Hitachi-LG Data Storage Inc Portable Super Multi Drive> at
> usbus1
> > umass0 on uhub4
> > umass0: <Hitachi-LG Data Storage Inc Portable Super Multi Drive, class
> > 0/0, rev 2.00/0.00, addr 14> on usbus1
> > umass0:  8070i (ATAPI) over Bulk-Only; quirks = 0x0000
> > umass0:1:0: Attached to scbus1
> > cd0 at umass-sim0 bus 0 scbus1 target 0 lun 0
> > cd0: <HL-DT-ST DVDRAM SP80NB80 RC00> Removable CD-ROM SCSI device
> > cd0: 40.000MB/s transfers
> > cd0: 0MB (1 0 byte sectors)
> > cd0: quirks=0x10<10_BYTE_ONLY>
> >
> > Detach messages are:
> >
> > ugen1.10: <Hitachi-LG Data Storage Inc Portable Super Multi Drive> at
> > usbus1 (disconnected)
> > umass0: at uhub4, port 2, addr 14 (disconnected)
> > cd0 at umass-sim0 bus 0 scbus1 target 0 lun 0
> > cd0: <HL-DT-ST DVDRAM SP80NB80 RC00>  detached
> > (cd0:umass-sim0:0:0:0): Periph destroyed
> > umass0: detached
> >
> >
>