usb: Assure Get Descriptor request is in separate microframe

The Kingston DT Ultimate USB 3.0 stick is sensitive to this first
Get Descriptor request and if the request is not in a separate
microframe, the stick refuses to operate. Add slight delay, which
is enough for one microframe to pass on any USB spec revision.

Signed-off-by: Marek Vasut <marex@denx.de>
Cc: Chin Liang See <clsee@altera.com>
Cc: Dinh Nguyen <dinguyen@opensource.altera.com>
Cc: Hans de Goede <hdegoede@redhat.com>
Cc: Stefan Roese <sr@denx.de>
Cc: Stephen Warren <swarren@nvidia.com>

diff --git a/common/usb.c b/common/usb.c
index 205041b6a62b2499abe4b29779b8bf683483fe26..8d9efe516b7571247b979f067b02962f0d6ad9d7 100644 (file)
--- a/common/usb.c
+++ b/common/usb.c
@@ -1077,6 +1077,14 @@ int usb_select_config(struct usb_device *dev)
        le16_to_cpus(&dev->descriptor.idProduct);
        le16_to_cpus(&dev->descriptor.bcdDevice);
 
+       /*
+        * Kingston DT Ultimate 32GB USB 3.0 seems to be extremely sensitive
+        * about this first Get Descriptor request. If there are any other
+        * requests in the first microframe, the stick crashes. Wait about
+        * one microframe duration here (1mS for USB 1.x , 125uS for USB 2.0).
+        */
+       mdelay(1);
+
        /* only support for one config for now */
        err = usb_get_configuration_len(dev, 0);
        if (err >= 0) {