sched: add exported arch_reinit_sched_domains() to header file.

[linux-2.6-omap-h63xx.git] / include / linux / usb / ch9.h

diff --git a/include/linux/usb/ch9.h b/include/linux/usb/ch9.h
index 245c72531228346982598506248d68fa03d16461..6169438ec5a2357c6341e1ae31f3cfc2cbac1ad2 100644 (file)
--- a/include/linux/usb/ch9.h
+++ b/include/linux/usb/ch9.h
@@ -1,8 +1,9 @@
 /*
- * This file holds USB constants and structures that are needed for USB
- * device APIs.  These are used by the USB device model, which is defined
- * in chapter 9 of the USB 2.0 specification.  Linux has several APIs in C
- * that need these:
+ * This file holds USB constants and structures that are needed for
+ * USB device APIs.  These are used by the USB device model, which is
+ * defined in chapter 9 of the USB 2.0 specification and in the
+ * Wireless USB 1.0 (spread around).  Linux has several APIs in C that
+ * need these:
  *
  * - the master/host side Linux-USB kernel driver API;
  * - the "usbfs" user space API; and
@@ -14,6 +15,19 @@
  *
  * There's also "Wireless USB", using low power short range radios for
  * peripheral interconnection but otherwise building on the USB framework.
+ *
+ * Note all descriptors are declared '__attribute__((packed))' so that:
+ *
+ * [a] they never get padded, either internally (USB spec writers
+ *     probably handled that) or externally;
+ *
+ * [b] so that accessing bigger-than-a-bytes fields will never
+ *     generate bus errors on any platform, even when the location of
+ *     its descriptor inside a bundle isn't "naturally aligned", and
+ *
+ * [c] for consistency, removing all doubt even when it appears to
+ *     someone that the two other points are non-issues for that
+ *     particular descriptor type.
  */
 
 #ifndef __LINUX_USB_CH9_H
@@ -167,12 +181,15 @@ struct usb_ctrlrequest {
 #define USB_DT_WIRE_ADAPTER            0x21
 #define USB_DT_RPIPE                   0x22
 
-/* conventional codes for class-specific descriptors */
-#define USB_DT_CS_DEVICE               0x21
-#define USB_DT_CS_CONFIG               0x22
-#define USB_DT_CS_STRING               0x23
-#define USB_DT_CS_INTERFACE            0x24
-#define USB_DT_CS_ENDPOINT             0x25
+/* Conventional codes for class-specific descriptors.  The convention is
+ * defined in the USB "Common Class" Spec (3.11).  Individual class specs
+ * are authoritative for their usage, not the "common class" writeup.
+ */
+#define USB_DT_CS_DEVICE               (USB_TYPE_CLASS | USB_DT_DEVICE)
+#define USB_DT_CS_CONFIG               (USB_TYPE_CLASS | USB_DT_CONFIG)
+#define USB_DT_CS_STRING               (USB_TYPE_CLASS | USB_DT_STRING)
+#define USB_DT_CS_INTERFACE            (USB_TYPE_CLASS | USB_DT_INTERFACE)
+#define USB_DT_CS_ENDPOINT             (USB_TYPE_CLASS | USB_DT_ENDPOINT)
 
 /* All standard descriptors have these 2 fields at the beginning */
 struct usb_descriptor_header {