On Thu, 19 Jul 2018, Bin Liu wrote:

> Based on USB2.0 Spec Section 11.12.5,
> 
>   "If a hub has per-port power switching and per-port current limiting,
>   an over-current on one port may still cause the power on another port
>   to fall below specific minimums. In this case, the affected port is
>   placed in the Power-Off state and C_PORT_OVER_CURRENT is set for the
>   port, but PORT_OVER_CURRENT is not set."
> 
> so let's check C_PORT_OVER_CURRENT too for over current condition.
> 
> Fixes: 08d1dec6f405 ("usb:hub set hub->change_bits when over-current happens")
> Cc: <sta...@vger.kernel.org>
> Tested-by: Alessandro Antenucci <antenu...@korg.it>
> Signed-off-by: Bin Liu <b-...@ti.com>
> ---
>  drivers/usb/core/hub.c | 8 ++++++--
>  1 file changed, 6 insertions(+), 2 deletions(-)
> 
> diff --git a/drivers/usb/core/hub.c b/drivers/usb/core/hub.c
> index fcae521df29b..1fb266809966 100644
> --- a/drivers/usb/core/hub.c
> +++ b/drivers/usb/core/hub.c
> @@ -1142,10 +1142,14 @@ static void hub_activate(struct usb_hub *hub, enum 
> hub_activation_type type)
>  
>               if (!udev || udev->state == USB_STATE_NOTATTACHED) {
>                       /* Tell hub_wq to disconnect the device or
> -                      * check for a new connection
> +                      * check for a new connection or over current condition.
> +                      * Based on USB2.0 Spec Section 11.12.5,
> +                      * C_PORT_OVER_CURRENT could be set while
> +                      * PORT_OVER_CURRENT is not. So check for any of them.
>                        */
>                       if (udev || (portstatus & USB_PORT_STAT_CONNECTION) ||
> -                         (portstatus & USB_PORT_STAT_OVERCURRENT))
> +                         (portstatus & USB_PORT_STAT_OVERCURRENT) ||
> +                         (portchange & USB_PORT_STAT_C_OVERCURRENT))
>                               set_bit(port1, hub->change_bits);
>  
>               } else if (portstatus & USB_PORT_STAT_ENABLE) {

Acked-by: Alan Stern <st...@rowland.harvard.edu>

--
To unsubscribe from this list: send the line "unsubscribe linux-usb" in
the body of a message to majord...@vger.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html

Reply via email to