usb: fix port reset

commit 891fb2cd4592b6fe76106a69e0ca40efbf82726a removed the implicit
detach before (re-)attaching in usb_attach().  Some usb host controllers
used that behavior though to do a port reset by a detach+attach
sequence.

This patch establishes old behavior by adding a new usb_reset() function
for port resets and putting it into use, thereby also unifying port
reset behavior of all host controllers.  The patch also adds asserts to
usb_attach() and usb_detach() to make sure the calls are symmetrical.

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

1 files changed, 1 insertions, 0 deletions

diff --git a/hw/usb.h b/hw/usb.h
index c08d469496..c6e1870e59 100644
--- a/hw/usb.h
+++ b/hw/usb.h
@@ -306,6 +306,7 @@ void usb_cancel_packet(USBPacket * p);
 
 void usb_attach(USBPort *port);
 void usb_detach(USBPort *port);
+void usb_reset(USBPort *port);
 void usb_wakeup(USBDevice *dev);
 int usb_generic_handle_packet(USBDevice *s, USBPacket *p);
 void usb_generic_async_ctrl_complete(USBDevice *s, USBPacket *p);