On Wed, Jul 31, 2019 at 01:08:50PM +0200, Philippe Mathieu-Daudé wrote: > On 7/30/19 7:45 PM, Guenter Roeck wrote: > > The following assert is seen once in a while while resetting the > > Linux kernel. > > > > qemu-system-x86_64: hw/usb/core.c:734: usb_ep_get: > > Assertion `dev != NULL' failed. > > > > The call to usb_ep_get() originates from ehci_execute(). > > Analysis and debugging shows that p->queue->dev can indeed be NULL > > in this function. Add check for this condition and return an error > > if it is seen. > > Your patch is not wrong as it corrects your case, but I wonder why we > get there. This assert seems to have catched a bug. > > Gerd, shouldn't we call usb_packet_cleanup() in ehci_reset() rather than > ehci_finalize()? Then we shouldn't need this patch. >
If you send me an alternate patch, I'll be happy to insert it into my build to give it some test coverage. Thanks, Guenter > > Signed-off-by: Guenter Roeck <li...@roeck-us.net> > > --- > > hw/usb/hcd-ehci.c | 5 +++++ > > 1 file changed, 5 insertions(+) > > > > diff --git a/hw/usb/hcd-ehci.c b/hw/usb/hcd-ehci.c > > index 62dab05..c759f3e 100644 > > --- a/hw/usb/hcd-ehci.c > > +++ b/hw/usb/hcd-ehci.c > > @@ -1348,6 +1348,11 @@ static int ehci_execute(EHCIPacket *p, const char > > *action) > > return -1; > > } > > > > + if (p->queue->dev == NULL) { > > + ehci_trace_guest_bug(p->queue->ehci, "No device attached to > > queue\n"); > > + return -1; > > + } > > + > > if (get_field(p->qtd.token, QTD_TOKEN_TBYTES) > BUFF_SIZE) { > > ehci_trace_guest_bug(p->queue->ehci, > > "guest requested more bytes than allowed"); > >