usb: gadget: function: phonet: balance usb_ep_disable calls

f_phonet's ->set_alt() method will call usb_ep_disable()
potentially on an endpoint which is already disabled. That's
something the gadget/function driver must guarantee that it's
always balanced.

In order to balance the calls, just make sure the endpoint
was enabled before by means of checking the validity of
driver_data.

Reported-by: Pali Rohár <pali.rohar@gmail.com>
Signed-off-by: Felipe Balbi <balbi@ti.com>

1 files changed, 4 insertions, 1 deletions

diff --git a/drivers/usb/gadget/function/f_phonet.c b/drivers/usb/gadget/function/f_phonet.c
index c89e96cfa3e4..c0c3ef272714 100644
--- a/drivers/usb/gadget/function/f_phonet.c
+++ b/drivers/usb/gadget/function/f_phonet.c
@@ -417,7 +417,10 @@ static int pn_set_alt(struct usb_function *f, unsigned intf, unsigned alt)
                         return -EINVAL;
 
                 spin_lock(&port->lock);
-                __pn_reset(f);
+
+                if (fp->in_ep->driver_data)
+                        __pn_reset(f);
+
                 if (alt == 1) {
                         int i;