Hi Mathias,
On Fri, Sep 28, 2018 at 03:35:10AM +0000, Peter Chen wrote:
>
> > > Cc: <stable@xxxxxxxxxxxxxxx>
> > > Reported-by: Peter Chen <peter.chen@xxxxxxx>
> > > Signed-off-by: Mathias Nyman <mathias.nyman@xxxxxxxxxxxxxxx>
> > > ---
> > > drivers/usb/host/xhci-ring.c | 7 +++++++
> > > 1 file changed, 7 insertions(+)
> > >
> > > diff --git a/drivers/usb/host/xhci-ring.c
> > > b/drivers/usb/host/xhci-ring.c index f0a99aa..3d314b8 100644
> > > --- a/drivers/usb/host/xhci-ring.c
> > > +++ b/drivers/usb/host/xhci-ring.c
> > > @@ -1552,6 +1552,13 @@ static void handle_port_status(struct xhci_hcd *xhci,
> > > goto cleanup;
> > > }
> > >
> > > + /* We might get interrupts after shared_hcd is removed */
> > > + if (port->rhub == &xhci->usb3_rhub && xhci->shared_hcd == NULL) {
> > > + xhci_dbg(xhci, "ignore port event for removed USB3 hcd\n");
> > > + bogus_port_status = true;
> > > + goto cleanup;
> > > + }
> > > +
> > > hcd = port->rhub->hcd;
> > > bus_state = &xhci->bus_state[hcd_index(hcd)];
> > > hcd_portnum = port->hcd_portnum;
> > >
> >
> > This probably only applies from 4.18 onwards, to test on older kernel try something
> > like this instead:
> >
> > diff --git a/drivers/usb/host/xhci-ring.c b/drivers/usb/host/xhci-ring.c index
> > 6996235..7925da9 100644
> > --- a/drivers/usb/host/xhci-ring.c
> > +++ b/drivers/usb/host/xhci-ring.c
> > @@ -1606,7 +1606,11 @@ static void handle_port_status(struct xhci_hcd *xhci,
> > hcd = xhci_to_hcd(xhci);
> > if ((major_revision == 0x03) != (hcd->speed >= HCD_USB3))
> > hcd = xhci->shared_hcd;
> > -
> > + if (!hcd) {
For testing on 4.14 I also added the debug print "ignore port event"
here as well. Maybe it should be there in the final -stable patch as
well.
> > + bogus_port_status = true;
> > + goto cleanup;
> > + }
> > if (major_revision == 0) {
> > xhci_warn(xhci, "Event for port %u not in "
> > "Extended Capabilities, ignoring.\n",
> >
> >
> > Jack, Peter, do these patches solve the remove issues you are seeing?
>
> At my two USB3 platforms, only apply the 1st patch can fix my problem. Maybe
> my USB3 port change interrupt occurs always before removing USB2 HCD.
>
> Peter
Ditto. I think the xhci_irq() is getting triggered by something during
usb_remove_hcd() (usb_disconnect on the root hub?) but is able to
complete before it returns. That is, the NULL pointer dereference is
resolved yet I don't see that "ignore port event for removed USB3 hcd"
message at all.
Regardless, it's good to have here just in case, so
Tested-by: Jack Pham <jackp@xxxxxxxxxxxxxx>
Will you be sending this as separate patches for -rc vs -stable?
Thanks,
Jack
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