[src/trunk]: src/sys/dev/usb Add some comments.

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

details:   https://anonhg.NetBSD.org/src/rev/29255313e3fa
branches:  trunk
changeset: 485199:29255313e3fa
user:      augustss <augustss%NetBSD.org@localhost>
date:      Fri Apr 21 20:58:56 2000 +0000

description:
Add some comments.

diffstat:

 sys/dev/usb/usb_subr.c |  18 +++++++++++++-----
 1 files changed, 13 insertions(+), 5 deletions(-)

diffs (83 lines):

diff -r 1c09e13838ad -r 29255313e3fa sys/dev/usb/usb_subr.c
--- a/sys/dev/usb/usb_subr.c    Fri Apr 21 20:13:41 2000 +0000
+++ b/sys/dev/usb/usb_subr.c    Fri Apr 21 20:58:56 2000 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: usb_subr.c,v 1.73 2000/04/21 15:58:55 augustss Exp $   */
+/*     $NetBSD: usb_subr.c,v 1.74 2000/04/21 20:58:56 augustss Exp $   */
 /*     $FreeBSD: src/sys/dev/usb/usb_subr.c,v 1.18 1999/11/17 22:33:47 n_hibma Exp $   */
 
 /*
@@ -526,6 +526,7 @@
        return (usbd_do_request(dev, &req, 0));
 }
 
+/* XXX should allow moving the device to the unconfigured state. */
 usbd_status
 usbd_set_config_no(dev, no, msg)
        usbd_device_handle dev;
@@ -548,6 +549,7 @@
        return (USBD_INVAL);
 }
 
+/* XXX should allow moving the device to the unconfigured state. */
 usbd_status
 usbd_set_config_index(dev, index, msg)
        usbd_device_handle dev;
@@ -575,7 +577,7 @@
                dev->config = 0;
        }
 
-       /* Figure out what config number to use. */
+       /* Get the short descriptor. */
        err = usbd_get_config_desc(dev, index, &cd);
        if (err)
                return (err);
@@ -583,6 +585,7 @@
        cdp = malloc(len, M_USB, M_NOWAIT);
        if (cdp == NULL)
                return (USBD_NOMEM);
+       /* Get the full descriptor. */
        err = usbd_get_desc(dev, UDESC_CONFIG, index, len, cdp);
        if (err)
                goto bad;
@@ -592,9 +595,11 @@
                err = USBD_INVAL;
                goto bad;
        }
+
+       /* Figure out if the device is self or bus powered. */
        selfpowered = 0;
        if (!(dev->quirks->uq_flags & UQ_BUS_POWERED) &&
-           cdp->bmAttributes & UC_SELF_POWERED) {
+           (cdp->bmAttributes & UC_SELF_POWERED)) {
                /* May be self powered. */
                if (cdp->bmAttributes & UC_BUS_POWERED) {
                        /* Must ask device. */
@@ -611,6 +616,8 @@
                 "selfpowered=%d, power=%d\n", 
                 dev->address, cdp->bmAttributes, 
                 selfpowered, cdp->bMaxPower * 2));
+
+       /* Check if we have enough power. */
 #ifdef USB_DEBUG
        if (dev->powersrc == NULL) {
                DPRINTF(("usbd_set_config_index: No power source?\n"));
@@ -632,6 +639,7 @@
        dev->power = power;
        dev->self_powered = selfpowered;
 
+       /* Set the actual configuration value. */
        DPRINTF(("usbd_set_config_index: set config %d\n",
                 cdp->bConfigurationValue));
        err = usbd_set_config(dev, cdp->bConfigurationValue);
@@ -641,8 +649,8 @@
                         cdp->bConfigurationValue, usbd_errstr(err)));
                goto bad;
        }
-       DPRINTF(("usbd_set_config_index: setting new config %d\n",
-                cdp->bConfigurationValue));
+
+       /* Allocate and fill interface data. */
        nifc = cdp->bNumInterface;
        dev->ifaces = malloc(nifc * sizeof(struct usbd_interface), 
                             M_USB, M_NOWAIT);