usb hub driver bug in overcurrent handling?

[Bin Liu <b-liu@ti.com>]

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

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?

Thanks,
-Bin.
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--- 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) {