PERFORCE change 129490 for review

[Hans Petter Selasky]

http://perforce.freebsd.org/chv.cgi?CH=129490

Change 129490 by hselasky at hselasky_laptop001 on 2007/11/25 10:24:32

	
	Update documentation.

Affected files ...

.. //depot/projects/usb/src/sys/dev/usb/README#21 edit

Differences ...

==== //depot/projects/usb/src/sys/dev/usb/README#21 (text+ko) ====

@@ -258,17 +258,19 @@
   force_short_xfer
 	This flag forces the last transmitted USB packet to be short.
 	A short packet has a length of less than "xfer->max_packet_size",
-	which derives from "wMaxPacketSize".
+	which derives from "wMaxPacketSize". This flag can be changed
+	during operation.
 
   short_xfer_ok
 	This flag allows the received transfer length, "xfer->actlen" 
 	to be less than "xfer->sumlen" upon completion of a transfer.
+	This flag can be changed during operation.
 
   use_polling
 	This flag can be used with any callback and will cause the
 	"usbd_transfer_start()" function to wait using "DELAY()",
 	without exiting any mutexes, until the transfer is finished or
-	has timed out.
+	has timed out. This flag can be changed during operation.
 
 	NOTE: If polling is used the "timeout" field should be non-zero!
 	NOTE: USBD_CANCELLED is returned in case of timeout
@@ -284,12 +286,12 @@
 	2) The failing USB transfer performs a successful transfer.
 
 	The purpose of this flag is to avoid races when multiple
-	transfers are queued for execution on an USB endpoint, and
-	the first executing transfer fails leading to the need
-	for clearing of stall for example. In this case this flag
-	is used to prevent the following USB transfers from being
-	executed at the same time the clear-stall command is
-	executed on the USB control endpoint.
+	transfers are queued for execution on an USB endpoint, and the
+	first executing transfer fails leading to the need for
+	clearing of stall for example. In this case this flag is used
+	to prevent the following USB transfers from being executed at
+	the same time the clear-stall command is executed on the USB
+	control endpoint. This flag can be changed during operation.
 
 	"BOF" is short for "Block On Failure"
 
@@ -304,17 +306,26 @@
 	stored in the "xfer->max_data_length". For control transfers
 	the USB kernel will allocate additional space for the 8-bytes
 	of SETUP header. These 8-bytes are not counted by the
-	"xfer->max_data_length" variable.
+	"xfer->max_data_length" variable. This flag can not be changed
+	during operation.
 
   ext_buffer
 	Setting this flag will cause that no DMA data buffer will be
 	allocated. Instead the USB client can use its own DMA buffer.
+	This flag can not be changed during operation.
 
   manual_status
 	Setting this flag causes that the STATUS stage of a control
 	transfer needs to be sent separately like a zero-length USB
 	frame. This flag has currently no effect on non-control
 	transfers. This flag is mostly useful for the USB device side.
+	This flag can be changed during operation.
+
+  bdma_enable
+	Setting this flag allows you to load virtual buffers directly
+	into DMA. Virtual buffers are loaded by a call to
+	"usbd_set_frame_data()".  This flag can not be changed during
+	operation.
 
 - The "bufsize" field sets the total buffer size in bytes. If
   this field is zero, "wMaxPacketSize" will be used, multiplied by the