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.
https://bugzilla.redhat.com//show_bug.cgi?id=1715801 maybe. > Gerd, shouldn't we call usb_packet_cleanup() in ehci_reset() rather than > ehci_finalize()? Then we shouldn't need this patch. The two ehci_queues_rip_all() calls in ehci_reset() should clean up everything properly. Can you try the patch below to see whenever a ehci_find_device failure is the root cause? thanks, Gerd diff --git a/hw/usb/hcd-ehci.c b/hw/usb/hcd-ehci.c index 62dab0592fa2..2b0a57772ed5 100644 --- a/hw/usb/hcd-ehci.c +++ b/hw/usb/hcd-ehci.c @@ -1644,6 +1644,10 @@ static EHCIQueue *ehci_state_fetchqh(EHCIState *ehci, int async) q->dev = ehci_find_device(q->ehci, get_field(q->qh.epchar, QH_EPCHAR_DEVADDR)); } + if (q->dev == NULL) { + fprintf(stderr, "%s: device %d not found\n", __func__, + get_field(q->qh.epchar, QH_EPCHAR_DEVADDR)); + } if (async && (q->qh.epchar & QH_EPCHAR_H)) {
