On 03.05.2016 22:51, Marek Vasut wrote:
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 <ma...@denx.de> Cc: Chin Liang See <cl...@altera.com> Cc: Dinh Nguyen <dingu...@opensource.altera.com> Cc: Hans de Goede <hdego...@redhat.com> Cc: Stefan Roese <s...@denx.de> Cc: Stephen Warren <swar...@nvidia.com> --- common/usb.c | 8 ++++++++ 1 file changed, 8 insertions(+) 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) {
Again my question, if this problem also occurs on other platforms with this USB key. A 1ms delay is not really a big deal, but its my general feeling that we should manifest such changes by testing on different platforms. Thanks, Stefan _______________________________________________ U-Boot mailing list U-Boot@lists.denx.de http://lists.denx.de/mailman/listinfo/u-boot
