[Qemu-devel] [PATCH] nec-usb-xhci: set the device state to USB_STATE_DEFAULT

[Zhang Shuaiyi <zhang_syi@massclouds.com>]

This patch is a rough fix to "hw/usb/core.c:401: usb_handle_packet:
 Assertion `dev->state == 3' failed.". Qemu will crash when a usb3
device redirect to Windows7 VM via nec-usb-xhci.

In extensible-host-controler-interface-usb-xhci.pdf P94(4.6.5
Address Device):
    • If the Block Set Address Request (BSR) flag = ‘1’
        • If the slot is in the Enabled state:
            ...
            • Set the Slot State in the Output Slot Context to Default.

BSR = ‘1’: Enabled state to Default state; BSR = ‘0’: Default state
to Addressed state. Try to call usb_device_reset to set device state
to USB_STATE_DEFAULT in xhci_address_slot wether bsr is zero.

Signed-off-by: Zhang Shuaiyi <zhang_syi@massclouds.com>
---
 hw/usb/hcd-xhci.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/hw/usb/hcd-xhci.c b/hw/usb/hcd-xhci.c
index 43ba615..e93b64e 100644
--- a/hw/usb/hcd-xhci.c
+++ b/hw/usb/hcd-xhci.c
@@ -2363,6 +2363,8 @@ static TRBCCode xhci_address_slot(XHCIState *xhci, unsigned int slotid,
     slot->uport = uport;
     slot->ctx = octx;
 
+    /* Make sure device is in USB_STATE_DEFAULT state */
+    usb_device_reset(dev);
     if (bsr) {
         slot_ctx[3] = SLOT_DEFAULT << SLOT_STATE_SHIFT;
     } else {
@@ -2370,7 +2372,6 @@ static TRBCCode xhci_address_slot(XHCIState *xhci, unsigned int slotid,
         uint8_t buf[1];
 
         slot_ctx[3] = (SLOT_ADDRESSED << SLOT_STATE_SHIFT) | slotid;
-        usb_device_reset(dev);
         memset(&p, 0, sizeof(p));
         usb_packet_addbuf(&p, buf, sizeof(buf));
         usb_packet_setup(&p, USB_TOKEN_OUT,
-- 
1.8.3.1