Merge tag 'usb-for-v4.7' of git://git.kernel.org/pub/scm/linux/kernel/git/balbi/usb into usb-next

Felipe writes:

usb: changes for v4.7 merge window

Here's the big USB Gadget pull request. This time
not as large as usual with only 57 non-merge
commits.

The most important part here is, again, all the work
on dwc3. This time around we're treating all
endpoints (except for control endpoint) exactly the
same. They all have the same amount of TRBs on the
ring, they all treat the ring as an actual ring with
a link TRB pointing to the head, etc.

We're also helping the host side burst (on
SuperSpeed GEN1 or GEN2 at least) for as long as
possible until the endpoint returns NRDY.

Other than this big TRB ring rework on dwc3, we also
have a dwc3-omap DMA initialization fix, some extra
debugfs files to aid in some odd debug sessions and
a complete removal of our FIFO resizing logic.

We have a new quirk for some dwc3 P3 quirk in some
implementations.

The rest is basically non-critical fixes and the
usual cleanups.

1 files changed, 19 insertions, 3 deletions

diff --git a/drivers/usb/gadget/composite.c b/drivers/usb/gadget/composite.c
index 524e233d48de..d67de0d22a2b 100644
--- a/drivers/usb/gadget/composite.c
+++ b/drivers/usb/gadget/composite.c
@@ -66,20 +66,36 @@ function_descriptors(struct usb_function *f,
 {
 	struct usb_descriptor_header **descriptors;
 
+	/*
+	 * NOTE: we try to help gadget drivers which might not be setting
+	 * max_speed appropriately.
+	 */
+
 	switch (speed) {
 	case USB_SPEED_SUPER_PLUS:
 		descriptors = f->ssp_descriptors;
-		break;
+		if (descriptors)
+			break;
+		/* FALLTHROUGH */
 	case USB_SPEED_SUPER:
 		descriptors = f->ss_descriptors;
-		break;
+		if (descriptors)
+			break;
+		/* FALLTHROUGH */
 	case USB_SPEED_HIGH:
 		descriptors = f->hs_descriptors;
-		break;
+		if (descriptors)
+			break;
+		/* FALLTHROUGH */
 	default:
 		descriptors = f->fs_descriptors;
 	}
 
+	/*
+	 * if we can't find any descriptors at all, then this gadget deserves to
+	 * Oops with a NULL pointer dereference
+	 */
+
 	return descriptors;
 }