summaryrefslogtreecommitdiff
path: root/common
diff options
context:
space:
mode:
authorMarek Vasut <marex@denx.de>2016-04-27 01:32:56 (GMT)
committerMarek Vasut <marex@denx.de>2016-05-06 18:06:56 (GMT)
commitef71290be9b70d8cfa63b506c7d93c5069f63c42 (patch)
treefe02836531de65bae903564c6b5b658bd7439639 /common
parentf647bf0ba36a5236d4bc7f93d39bfacfb1cfe6c7 (diff)
downloadu-boot-ef71290be9b70d8cfa63b506c7d93c5069f63c42.tar.xz
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>
Diffstat (limited to 'common')
-rw-r--r--common/usb.c8
1 files changed, 8 insertions, 0 deletions
diff --git a/common/usb.c b/common/usb.c
index 205041b..8d9efe5 100644
--- 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) {