usb: raw-gadget: return -EINVAL if no proper ep address available

If we try to use raw_ioctl_ep_enable() for ep5in on a hardware that
only support from ep1-ep4 for both in and out direction, it will return
-EBUSY originally.

I think it will be more intuitive if we return -EINVAL, because -EBUSY
sounds like ep5in is not available now, but might be available in the
future.

Reviewed-by: Andrey Konovalov <andreyknvl@gmail.com>
Signed-off-by: Wei Ming Chen <jj251510319013@gmail.com>
Link: https://lore.kernel.org/r/20220311082944.4881-1-jj251510319013@gmail.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/usb/gadget/legacy/raw_gadget.c b/drivers/usb/gadget/legacy/raw_gadget.c
index 135e75b..8d40a1f 100644 (file)
--- a/drivers/usb/gadget/legacy/raw_gadget.c
+++ b/drivers/usb/gadget/legacy/raw_gadget.c
@@ -758,6 +758,7 @@ static int raw_ioctl_ep_enable(struct raw_dev *dev, unsigned long value)
        unsigned long flags;
        struct usb_endpoint_descriptor *desc;
        struct raw_ep *ep;
+       bool ep_props_matched = false;
 
        desc = memdup_user((void __user *)value, sizeof(*desc));
        if (IS_ERR(desc))
@@ -787,13 +788,14 @@ static int raw_ioctl_ep_enable(struct raw_dev *dev, unsigned long value)
 
        for (i = 0; i < dev->eps_num; i++) {
                ep = &dev->eps[i];
-               if (ep->state != STATE_EP_DISABLED)
-                       continue;
                if (ep->addr != usb_endpoint_num(desc) &&
                                ep->addr != USB_RAW_EP_ADDR_ANY)
                        continue;
                if (!usb_gadget_ep_match_desc(dev->gadget, ep->ep, desc, NULL))
                        continue;
+               ep_props_matched = true;
+               if (ep->state != STATE_EP_DISABLED)
+                       continue;
                ep->ep->desc = desc;
                ret = usb_ep_enable(ep->ep);
                if (ret < 0) {
@@ -815,8 +817,13 @@ static int raw_ioctl_ep_enable(struct raw_dev *dev, unsigned long value)
                goto out_unlock;
        }
 
-       dev_dbg(&dev->gadget->dev, "fail, no gadget endpoints available\n");
-       ret = -EBUSY;
+       if (!ep_props_matched) {
+               dev_dbg(&dev->gadget->dev, "fail, bad endpoint descriptor\n");
+               ret = -EINVAL;
+       } else {
+               dev_dbg(&dev->gadget->dev, "fail, no endpoints available\n");
+               ret = -EBUSY;
+       }
 
 out_free:
        kfree(desc);