[PATCH 3.16 273/366] usb: core: handle hub C_PORT_OVER_CURRENT condition

Ben Hutchings
2018-11-12T05:48:31Z

From: Bin Liu <b-liu@ti.com>

commit 249a32b7eeb3edb6897dd38f89651a62163ac4ed upstream.

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")
Tested-by: Alessandro Antenucci <antenucci@korg.it>
Signed-off-by: Bin Liu <b-liu@ti.com>
Acked-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
[bwh: Backported to 3.16: adjust context]
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
---
drivers/usb/core/hub.c | 8 ++++++--
1 file changed, 6 insertions(+), 2 deletions(-)

--- a/drivers/usb/core/hub.c
+++ b/drivers/usb/core/hub.c
@@ -1119,10 +1119,14 @@ static void hub_activate(struct usb_hub

if (!udev || udev->state == USB_STATE_NOTATTACHED) {
/* Tell khubd 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) {