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...@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

_______________________________________________
U-Boot mailing list
U-Boot@lists.denx.de
https://lists.denx.de/listinfo/u-boot

Reply via email to