On Fri, Dec 31, 2010 at 12:21:55PM -0500, Alan Stern wrote:
> On Thu, 30 Dec 2010, Sarah Sharp wrote:
>
> > Once the xHCI host controller has a USB 2.0 roothub and a USB 3.0 roothub,
> > the TT field of the USB 2.0 roothub usb device will no longer be null.
>
> Do you mean the tt field of the root hub usb_hub structure? It doesn't
> need to be set unless xHCI root hubs really do contain a Transaction
> Translator, and from what you write below I suspect they don't.
Yes, the xHCI host controller doesn't contain a TT.
> > To
> > check whether a LS/FS device is plugged into the HS roothub, see if the
> > parent's parent is NULL. We don't need the TT information if the LS/FS
> > device is plugged into a roothub port.
>
> Then udev->tt shouldn't be set if udev is plugged into an xHCI root
> hub. Maybe you should change that instead of changing this.
Ok. Are you suggesting I change this code in hub_port_init():
/* Set up TT records, if needed */
if (hdev->tt) {
udev->tt = hdev->tt;
udev->ttport = hdev->ttport;
} else if (udev->speed != USB_SPEED_HIGH
&& hdev->speed == USB_SPEED_HIGH) {
udev->tt = &hub->tt;
udev->ttport = port1;
}
to
/* Set up TT records, if needed.
* The xHCI USB 2.0 roothub doesn't have a TT.
*/
if (hdev->tt) {
udev->tt = hdev->tt;
udev->ttport = hdev->ttport;
} else if (udev->speed != USB_SPEED_HIGH
&& hdev->speed == USB_SPEED_HIGH
&& (hdev->parent ||
hcd->driver->flags & HCD_USB3) {
udev->tt = &hub->tt;
udev->ttport = port1;
}
?
>
> > This bug would only show up after the split roothub code is added.
> >
> > Signed-off-by: Sarah Sharp <sarah.a.sharp@xxxxxxxxxxxxxxx>
> > ---
> > drivers/usb/host/xhci-mem.c | 4 ++--
> > 1 files changed, 2 insertions(+), 2 deletions(-)
> >
> > diff --git a/drivers/usb/host/xhci-mem.c b/drivers/usb/host/xhci-mem.c
> > index 1d0f45f..76a9f1c 100644
> > --- a/drivers/usb/host/xhci-mem.c
> > +++ b/drivers/usb/host/xhci-mem.c
> > @@ -870,9 +870,9 @@ int xhci_setup_addressable_virt_dev(struct xhci_hcd *xhci, struct usb_device *ud
> > dev->port = top_dev->portnum;
> > xhci_dbg(xhci, "Set root hub portnum to %d\n", top_dev->portnum);
> >
> > - /* Is this a LS/FS device under a HS hub? */
> > + /* Is this a LS/FS device under an external HS hub? */
> > if ((udev->speed == USB_SPEED_LOW || udev->speed == USB_SPEED_FULL) &&
>
> These tests are redundant. udev->tt will not be set unless the speed
> is LOW or FULL.
Ok, I'll remove them.
> > - udev->tt) {
> > + udev->parent->parent && udev->tt) {
> > slot_ctx->tt_info = udev->tt->hub->slot_id;
> > slot_ctx->tt_info |= udev->ttport << 8;
> > if (udev->tt->multi)
Sarah Sharp
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