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SubjectRe: [PATCH] Revert "usb: Reset USB-3 devices on USB-3 link bounce"
Hi,

On 26-01-15 16:30, Zhuang Jin Can wrote:
> This revert a82b76f7fa6154e8ab2d8071842a3e38b9c0d0ff.
>
> The commit causes an extra reset in remote wakeup as described in:
> http://www.spinics.net/lists/linux-usb/msg119080.html
>
> Signed-off-by: Zhuang Jin Can <jin.can.zhuang@intel.com>

No objection from me (*) against reverting this, as it was fixing a
rather obscure (but non the less real) issue, and the issue it
causes seems to be a bigger one.

Regards,

Hans

*) I'm the author of the original patch


> ---
> drivers/usb/core/hub.c | 34 +++++++++-------------------------
> 1 file changed, 9 insertions(+), 25 deletions(-)
>
> diff --git a/drivers/usb/core/hub.c b/drivers/usb/core/hub.c
> index aeb50bb..89d009a 100644
> --- a/drivers/usb/core/hub.c
> +++ b/drivers/usb/core/hub.c
> @@ -4882,7 +4882,7 @@ static void hub_port_connect_change(struct usb_hub *hub, int port1,
> static void port_event(struct usb_hub *hub, int port1)
> __must_hold(&port_dev->status_lock)
> {
> - int connect_change, reset_device = 0;
> + int connect_change;
> struct usb_port *port_dev = hub->ports[port1 - 1];
> struct usb_device *udev = port_dev->child;
> struct usb_device *hdev = hub->hdev;
> @@ -4970,30 +4970,14 @@ static void port_event(struct usb_hub *hub, int port1)
> if (hub_port_reset(hub, port1, NULL,
> HUB_BH_RESET_TIME, true) < 0)
> hub_port_disable(hub, port1, 1);
> - } else
> - reset_device = 1;
> - }
> -
> - /*
> - * On disconnect USB3 protocol ports transit from U0 to
> - * SS.Inactive to Rx.Detect. If this happens a warm-
> - * reset is not needed, but a (re)connect may happen
> - * before hub_wq runs and sees the disconnect, and the
> - * device may be an unknown state.
> - *
> - * If the port went through SS.Inactive without hub_wq
> - * seeing it the C_LINK_STATE change flag will be set,
> - * and we reset the dev to put it in a known state.
> - */
> - if (reset_device || (udev && hub_is_superspeed(hub->hdev)
> - && (portchange & USB_PORT_STAT_C_LINK_STATE)
> - && (portstatus & USB_PORT_STAT_CONNECTION))) {
> - usb_unlock_port(port_dev);
> - usb_lock_device(udev);
> - usb_reset_device(udev);
> - usb_unlock_device(udev);
> - usb_lock_port(port_dev);
> - connect_change = 0;
> + } else {
> + usb_unlock_port(port_dev);
> + usb_lock_device(udev);
> + usb_reset_device(udev);
> + usb_unlock_device(udev);
> + usb_lock_port(port_dev);
> + connect_change = 0;
> + }
> }
>
> if (connect_change)
>


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