usb: cancel async packets on unplug

This patch adds USBBusOps struct with (for now) only a single callback
which is called when a device is about to be destroyed.  The USB Host
adapters are implementing this callback and use it to cancel any async
requests which might be in flight before the device actually goes away.

Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>

1 files changed, 7 insertions, 1 deletions

diff --git a/hw/usb.h b/hw/usb.h
index 98824009b9..609720893d 100644
--- a/hw/usb.h
+++ b/hw/usb.h
@@ -132,6 +132,7 @@
 #define USB_ENDPOINT_XFER_INT		3
 
 typedef struct USBBus USBBus;
+typedef struct USBBusOps USBBusOps;
 typedef struct USBPort USBPort;
 typedef struct USBDevice USBDevice;
 typedef struct USBDeviceInfo USBDeviceInfo;
@@ -323,6 +324,7 @@ void musb_set_size(MUSBState *s, int epnum, int size, int is_tx);
 
 struct USBBus {
     BusState qbus;
+    USBBusOps *ops;
     int busnr;
     int nfree;
     int nused;
@@ -331,7 +333,11 @@ struct USBBus {
     QTAILQ_ENTRY(USBBus) next;
 };
 
-void usb_bus_new(USBBus *bus, DeviceState *host);
+struct USBBusOps {
+    void (*device_destroy)(USBBus *bus, USBDevice *dev);
+};
+
+void usb_bus_new(USBBus *bus, USBBusOps *ops, DeviceState *host);
 USBBus *usb_bus_find(int busnr);
 void usb_qdev_register(USBDeviceInfo *info);
 void usb_qdev_register_many(USBDeviceInfo *info);