usb: core: hub: modify hub reset logic in hub driver

Currently if port power is turned off by user on hub port
using USBDEVFS then port power is turned back ON
by hub driver.
This commit modifies hub reset logic in hub_port_connect() to prevent
hub driver from turning back the port power ON if port is not owned
by kernel.

Signed-off-by: Deepak Das <deepakdas.linux@gmail.com>
Acked-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/usb/core/hub.c b/drivers/usb/core/hub.c
index b4bfa3ac4b12207986972ff040897683817487cc..3e9c4d477d1accd2be9cdedc340619a6abc711fb 100644 (file)
--- a/drivers/usb/core/hub.c
+++ b/drivers/usb/core/hub.c
@@ -4655,9 +4655,13 @@ static void hub_port_connect(struct usb_hub *hub, int port1, u16 portstatus,
        if (!(portstatus & USB_PORT_STAT_CONNECTION) ||
                        test_bit(port1, hub->removed_bits)) {
 
-               /* maybe switch power back on (e.g. root hub was reset) */
+               /*
+                * maybe switch power back on (e.g. root hub was reset)
+                * but only if the port isn't owned by someone else.
+                */
                if (hub_is_port_power_switchable(hub)
-                               && !port_is_power_on(hub, portstatus))
+                               && !port_is_power_on(hub, portstatus)
+                               && !port_dev->port_owner)
                        set_port_feature(hdev, port1, USB_PORT_FEAT_POWER);
 
                if (portstatus & USB_PORT_STAT_ENABLE)