On Mon, Jan 09, 2012 at 03:24:06PM -0500, Alan Stern wrote:
> On Mon, 9 Jan 2012, Felipe Balbi wrote:
>
> > > Actually it does help: In that situation, the uas driver can print a
> > > warning message telling the user to plug the device into a different
> > > controller. We already do something very much like that when a
> > > high-speed-capable device is plugged into a full-speed controller; see
> > > check_highspeed() in hub.c. Is there any way to do the same thing when
> > > a SuperSpeed-capable device is plugged into a USB <= 2.0 controller?
> >
> > you should be able to implement something like that by checking your
> > Device Capability Descriptor which comes with the BOS descriptor set.
> >
> > Then you can check wSpeedSuppoted field on that device, if it has the
> > SuperSpeed bit enabled and you're attached to <=USB_SPEED_HIGH, then you
> > can warn.
>
> Anybody have the time to do this? :-)
Done, although untested. lsusb also needs to be fixed to fetch the BOS
descriptor if it sees a USB 2.1 device. I'll send that patch shortly.
Sarah Sharp
diff --git a/drivers/usb/core/hub.c b/drivers/usb/core/hub.c
index db6b751..1f92ce8 100644
--- a/drivers/usb/core/hub.c
+++ b/drivers/usb/core/hub.c
@@ -3164,6 +3164,16 @@ check_highspeed (struct usb_hub *hub, struct usb_device *udev, int port1)
kfree(qual);
}
+static void check_superspeed(struct usb_hub *hub, struct usb_device *udev,
+ int port1)
+{
+ if (le16_to_cpu(udev->descriptor.bcdUSB) < 0x0300 &&
+ dev->bos->ss_cap)
+ /* BOS descriptor should have already been fetched by now. */
+ dev_info(&udev->dev, "not running at top speed; "
+ "connect to a SuperSpeed hub or host\n");
+}
+
static unsigned
hub_power_remaining (struct usb_hub *hub)
{
@@ -3383,6 +3393,7 @@ static void hub_port_connect_change(struct usb_hub *hub, int port1,
&& udev->speed == USB_SPEED_FULL
&& highspeed_hubs != 0)
check_highspeed (hub, udev, port1);
+ check_super_speed(hub, udev, port1);
/* Store the parent's children[] pointer. At this point
* udev becomes globally accessible, although presumably
