On Wed, 2010-04-28 at 12:05 -0400, Alan Stern wrote:
> On Thu, 29 Apr 2010, Andiry Xu wrote:
>
> > >From 7fab4880295b3af163342570d3c33ac0b51d29b5 Mon Sep 17 00:00:00 2001
> > From: Andiry Xu <andiry.xu@xxxxxxx>
> > Date: Thu, 29 Apr 2010 00:21:38 +0800
> > Subject: [PATCH] usbcore: Do not disable USB3 protocol ports in hub_activate
> >
> > When USB3 protocol port detects an USB3.0 device attach, the port will
> > automatically transition to the Enabled state upon the completion
> > of successful link training.
> >
> > Do not disable USB3 protocol ports in hub_activate(), or USB3.0 device
> > will fail to be recognized if xHCI bus power management is implemented.
>
> I would prefer to see xhci-hcd changed to register two separate root
> hubs. But until that gets done, something like this appears to be
> necessary.
Agreed. xhci-hcd behavior should comply with USB3.0 spec. The root hub
should appear as two separate root hubs. This patch is a temporary
workaround.
> > Signed-off-by: Andiry Xu <andiry.xu@xxxxxxx>
> > ---
> > drivers/usb/core/hub.c | 16 ++++++++++++++--
> > 1 files changed, 14 insertions(+), 2 deletions(-)
> >
> > diff --git a/drivers/usb/core/hub.c b/drivers/usb/core/hub.c
> > index 5c483fa..96bad49 100644
> > --- a/drivers/usb/core/hub.c
> > +++ b/drivers/usb/core/hub.c
> > @@ -745,8 +745,20 @@ static void hub_activate(struct usb_hub *hub, enum hub_activation_type type)
> > !(portstatus & USB_PORT_STAT_CONNECTION) ||
> > !udev ||
> > udev->state == USB_STATE_NOTATTACHED)) {
> > - clear_port_feature(hdev, port1, USB_PORT_FEAT_ENABLE);
> > - portstatus &= ~USB_PORT_STAT_ENABLE;
> > + /*
> > + * USB3 protocol ports will automatically transition
> > + * to Enabled state when detect an USB3.0 device attach.
> > + * Do not disable USB3 protocol ports.
> > + * FIXME: USB3 root hub and external hubs are treated
> > + * differently here.
> > + */
> > + if ((hdev->descriptor.bDeviceProtocol != 3) ||
> > + ((!hdev->parent) &&
> > + !(portstatus & USB_PORT_STAT_SUPER_SPEED))) {
>
> You've got lots of excess ()'s here; they tend to clutter up the text.
I will remove unnecessary parentheses. Thanks.
Andiry Xu
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