[src/trunk]: src/sys/dev/usb uvideo(4): Fix USB interface numbering.

[riastradh <riastradh%NetBSD.org@localhost>]

details:   https://anonhg.NetBSD.org/src/rev/d1217e92ee48
branches:  trunk
changeset: 359561:d1217e92ee48
user:      riastradh <riastradh%NetBSD.org@localhost>
date:      Sun Jan 09 18:27:23 2022 +0000

description:
uvideo(4): Fix USB interface numbering.

Don't try to be clever and count -- just use bInterfaceNumber.

The previous logic to count interface descriptors failed to consider
interfaces with alternate settings, which led it to pass an invalid
interface number to usbd_device2interface_handle.

It is simpler to just use the recorded bInterfaceNumber, which is
guaranteed by the USB spec to be zero-indexed and below
bNumInterfaces as we need.

diffstat:

 sys/dev/usb/uvideo.c |  22 ++++++++--------------
 1 files changed, 8 insertions(+), 14 deletions(-)

diffs (78 lines):

diff -r f138ae3ecb06 -r d1217e92ee48 sys/dev/usb/uvideo.c
--- a/sys/dev/usb/uvideo.c      Sun Jan 09 18:22:31 2022 +0000
+++ b/sys/dev/usb/uvideo.c      Sun Jan 09 18:27:23 2022 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: uvideo.c,v 1.63 2021/11/14 08:32:07 andvar Exp $       */
+/*     $NetBSD: uvideo.c,v 1.64 2022/01/09 18:27:23 riastradh Exp $    */
 
 /*
  * Copyright (c) 2008 Patrick Mahoney
@@ -42,7 +42,7 @@
  */
 
 #include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: uvideo.c,v 1.63 2021/11/14 08:32:07 andvar Exp $");
+__KERNEL_RCSID(0, "$NetBSD: uvideo.c,v 1.64 2022/01/09 18:27:23 riastradh Exp $");
 
 #ifdef _KERNEL_OPT
 #include "opt_usb.h"
@@ -328,8 +328,7 @@
 static usbd_status             uvideo_stream_init(
        struct uvideo_stream *,
        struct uvideo_softc *,
-       const usb_interface_descriptor_t *,
-       uint8_t);
+       const usb_interface_descriptor_t *);
 static usbd_status             uvideo_stream_init_desc(
        struct uvideo_stream *,
        const usb_interface_descriptor_t *,
@@ -490,7 +489,6 @@
        const usb_interface_descriptor_t *ifdesc;
        struct uvideo_stream *vs;
        usbd_status err;
-       uint8_t ifaceidx;
 
        sc->sc_dev = self;
 
@@ -522,10 +520,7 @@
 
        /* iterate through interface descriptors and initialize softc */
        usb_desc_iter_init(sc->sc_udev, &iter);
-       for (ifaceidx = 0;
-            (ifdesc = usb_desc_iter_next_interface(&iter)) != NULL;
-            ++ifaceidx)
-       {
+       while ((ifdesc = usb_desc_iter_next_interface(&iter)) != NULL) {
                if (ifdesc->bLength < USB_INTERFACE_DESCRIPTOR_SIZE) {
                        DPRINTFN(50, ("uvideo_attach: "
                                      "ignoring incorrect descriptor len=%d\n",
@@ -562,8 +557,7 @@
                        vs = uvideo_find_stream(sc, ifdesc->bInterfaceNumber);
                        if (vs == NULL) {
                                vs = uvideo_stream_alloc();
-                               err = uvideo_stream_init(vs, sc, ifdesc,
-                                                        ifaceidx);
+                               err = uvideo_stream_init(vs, sc, ifdesc);
                                if (err != USBD_NORMAL_COMPLETION) {
                                        DPRINTF(("uvideo_attach: "
                                                 "error initializing stream: "
@@ -1026,8 +1020,7 @@
 static usbd_status
 uvideo_stream_init(struct uvideo_stream *vs,
                   struct uvideo_softc *sc,
-                  const usb_interface_descriptor_t *ifdesc,
-                  uint8_t idx)
+                  const usb_interface_descriptor_t *ifdesc)
 {
        uWord len;
        usbd_status err;
@@ -1043,7 +1036,8 @@
        vs->vs_current_format.priv = -1;
        vs->vs_xfer_type = 0;
 
-       err = usbd_device2interface_handle(sc->sc_udev, idx, &vs->vs_iface);
+       err = usbd_device2interface_handle(sc->sc_udev, vs->vs_ifaceno,
+           &vs->vs_iface);
        if (err != USBD_NORMAL_COMPLETION) {
                DPRINTF(("uvideo_stream_init: "
                         "error getting vs interface: "