[U-Boot] [PATCH 07/14] usb: Read device descriptor after device is addressed for xHCI

[Bin Meng <bmeng.cn@gmail.com>]

For xHCI it is not possible to read a device descriptor before it
has been assigned an address. That's why usb_setup_descriptor()
was called with 'do_read' being false. But we really need try to
read the device descriptor before starting any real communication
with the default control endpoint.

Signed-off-by: Bin Meng <bmeng.cn@gmail.com>
---

 common/usb.c | 11 +++++++++++
 1 file changed, 11 insertions(+)

diff --git a/common/usb.c b/common/usb.c
index 88cee81..8d27bc7 100644
--- a/common/usb.c
+++ b/common/usb.c
@@ -1052,6 +1052,17 @@ static int usb_prepare_device(struct usb_device *dev, int addr, bool do_read,
 
 	mdelay(10);	/* Let the SET_ADDRESS settle */
 
+	/*
+	 * If we haven't read device descriptor before, read it here
+	 * after device is assigned an address. This is only applicable
+	 * to xHCI so far.
+	 */
+	if (!do_read) {
+		err = usb_setup_descriptor(dev, true);
+		if (err)
+			return err;
+	}
+
 	return 0;
 }
 
-- 
2.9.2