On Wed, 28 Nov 2018, Mathias Nyman wrote:
> When initializing a hub we want to give a USB3 port in link training
> the same debounce delay time before autosuspening the hub as already
> trained, connected enabled ports.
>
> USB3 ports won't reach the enabled state with "current connect status" and
> "connect status change" bits set until the USB3 link training finishes.
>
> Catching the port in link training (polling) and adding the debounce delay
> prevents unnecessary failed attempts to autosuspend the hub.
>
> Signed-off-by: Mathias Nyman <mathias.nyman@xxxxxxxxxxxxxxx>
> ---
> drivers/usb/core/hub.c | 10 ++++++++++
> 1 file changed, 10 insertions(+)
>
> diff --git a/drivers/usb/core/hub.c b/drivers/usb/core/hub.c
> index 0f9381b..009f928 100644
> --- a/drivers/usb/core/hub.c
> +++ b/drivers/usb/core/hub.c
> @@ -1112,6 +1112,16 @@ static void hub_activate(struct usb_hub *hub, enum hub_activation_type type)
> USB_PORT_FEAT_ENABLE);
> }
>
> + /*
> + * Add debounce if USB3 link is in polling/link training state.
> + * Link will automatically transition to Enabled state after
> + * link training completes.
> + */
> + if (hub_is_superspeed(hdev) &&
> + ((portstatus & USB_PORT_STAT_LINK_STATE) ==
> + USB_SS_PORT_LS_POLLING))
> + need_debounce_delay = true;
> +
> /* Clear status-change flags; we'll debounce later */
> if (portchange & USB_PORT_STAT_C_CONNECTION) {
> need_debounce_delay = true;
Acked-by: Alan Stern <stern@xxxxxxxxxxxxxxxxxxx>
