On Fri, 13 Jul 2018, Bin Liu wrote:
> Hi,
>
> I got a report saying that when overcurrent happens in one of the hub
> downstream ports, USB_PORT_STAT_OVERCURRENT is not set in portstatus,
> instead USB_PORT_STAT_C_OVERCURRENT is set in portchange, then the
> overcurrent condition is not handled in hub_event().
>
> The following patch solves the issue.
>
> t a/drivers/usb/core/hub.c b/drivers/usb/core/hub.c
> index 442be7f312f6..118557acc74b 100644
> --- a/drivers/usb/core/hub.c
> +++ b/drivers/usb/core/hub.c
> @@ -1144,7 +1144,8 @@ static void hub_activate(struct usb_hub *hub, enum hub_activation_type type)
> * check for a new connection
> */
> 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) {
Please also update the immediately preceding comment.
> The usb2.0 spec section 11.12.5 states
> "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 is the patch above a proper fix? or something else might be missing?
It certainly seems like a reasonable thing to do. If you say it fixes
the problem, we can add it in.
Alan Stern
--
To unsubscribe from this list: send the line "unsubscribe linux-usb" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
