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.
> 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.
> + clear_port_feature(hdev, port1,
> + USB_PORT_FEAT_ENABLE);
> + portstatus &= ~USB_PORT_STAT_ENABLE;
> + }
> }
Alan Stern
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