[PATCH QEMU HCI-8.0 v5 08/13] usb-host: skip product-string read on CPR incoming #VSTOR-137800

[Andrey Drobyshev <andrey.drobyshev@virtuozzo.com>]

usb_host_open() reads the product string descriptor from the device
with a synchronous control transfer.  On the CPR target this runs while
the device is being handed over, and the transfer can block there,
hanging the incoming migration.

The string only fills the cosmetic product_desc, so skip the read when
we're the CPR target and fall back to the synthetic "host:bus.addr"
name.

Signed-off-by: Andrey Drobyshev <andrey.drobyshev@virtuozzo.com>
---
 hw/usb/host-libusb.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/hw/usb/host-libusb.c b/hw/usb/host-libusb.c
index a14a3748838..6b8c0cf0a82 100644
--- a/hw/usb/host-libusb.c
+++ b/hw/usb/host-libusb.c
@@ -1097,7 +1097,7 @@ static int usb_host_open(USBHostDevice *s, libusb_device *dev, int hostfd)
     udev->speed = speed_map[libusb_speed];
     usb_host_speed_compat(s);
 
-    if (s->ddesc.iProduct) {
+    if (s->ddesc.iProduct && !cpr_is_incoming()) {
         libusb_get_string_descriptor_ascii(s->dh, s->ddesc.iProduct,
                                            (unsigned char *)udev->product_desc,
                                            sizeof(udev->product_desc));

-- 
2.47.1