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linux-next/drivers/usb
David Brownell 77078570ab [PATCH] USB: ehci-hcd - fix page pointer allocation in itd_patch()
The itd_patch() function is responsible for allocating entries in the
buffer page pointer list of the iTD.  Particularly, a new page pointer
is needed every time when buffer data crosses a page boundary.

However, there is a bug in the allocation logic: the function does not
allocate a new entry when the current transaction is the first
transaction in the iTD (as indicated by first!=0).

The consequence is that, when the data of the first transaction begins
somewhere at the end of a page so that it actually does cross the page
boundary, no new page pointer is allocated.  This means that the data
at the end of the first transaction (beyond the page boundary) will be
accessed by the HC using the second page pointer, which is zero.
Furthermore, the first page pointer will be later overwritten by the
page pointers of the other transactions, which will garble it because
the value is or-ed into the iTD field.

All this particular check (for !first) does is cause incorrect
behaviour, so it should be entirely removed (and with it the variable
first that is not used for anything else).

Signed-off-by: Clemens Ladisch <clemens@ladisch.de>
Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2005-06-27 14:44:00 -07:00
..
atm [PATCH] USB: usbatm kcalloc cleanup 2005-06-27 14:43:58 -07:00
class [PATCH] USB: fix acm trouble with terminals 2005-06-27 14:43:45 -07:00
core [PATCH] usbcore: register root hub in usb_add_hcd 2005-06-27 14:43:49 -07:00
gadget [PATCH] USB gadget: drain rndis response queue on disconnect 2005-06-27 14:44:00 -07:00
host [PATCH] USB: ehci-hcd - fix page pointer allocation in itd_patch() 2005-06-27 14:44:00 -07:00
image [PATCH] USB: Spelling fixes for drivers/usb. 2005-05-03 23:31:52 -07:00
input [PATCH] USB: fix hid core to return proper error code from probe 2005-06-22 23:01:09 -07:00
media [PATCH] pwc-uncompress warning fix 2005-06-23 09:45:35 -07:00
misc [PATCH] USB: upgrade of the idmouse driver 2005-06-27 14:43:53 -07:00
mon [PATCH] better USB_MON dependencies 2005-06-23 10:04:15 -07:00
net [PATCH] USB: check for device in zd1201_resume 2005-06-27 14:43:47 -07:00
serial [PATCH] USB: add ability for usb-serial drivers to determine if their write urb is currently being used. 2005-06-27 14:43:47 -07:00
storage [PATCH] Cleanup patch for process freezing 2005-06-25 17:10:13 -07:00
Kconfig Linux-2.6.12-rc2 2005-04-16 15:20:36 -07:00
Makefile [PATCH] USB: Add isp116x-hcd USB host controller driver 2005-06-27 14:43:42 -07:00
README Linux-2.6.12-rc2 2005-04-16 15:20:36 -07:00
usb-skeleton.c Linux-2.6.12-rc2 2005-04-16 15:20:36 -07:00

To understand all the Linux-USB framework, you'll use these resources:

    * This source code.  This is necessarily an evolving work, and
      includes kerneldoc that should help you get a current overview.
      ("make pdfdocs", and then look at "usb.pdf" for host side and
      "gadget.pdf" for peripheral side.)  Also, Documentation/usb has
      more information.

    * The USB 2.0 specification (from www.usb.org), with supplements
      such as those for USB OTG and the various device classes.
      The USB specification has a good overview chapter, and USB
      peripherals conform to the widely known "Chapter 9".

    * Chip specifications for USB controllers.  Examples include
      host controllers (on PCs, servers, and more); peripheral
      controllers (in devices with Linux firmware, like printers or
      cell phones); and hard-wired peripherals like Ethernet adapters.

    * Specifications for other protocols implemented by USB peripheral
      functions.  Some are vendor-specific; others are vendor-neutral
      but just standardized outside of the www.usb.org team.

Here is a list of what each subdirectory here is, and what is contained in
them.

core/		- This is for the core USB host code, including the
		  usbfs files and the hub class driver ("khubd").

host/		- This is for USB host controller drivers.  This
		  includes UHCI, OHCI, EHCI, and others that might
		  be used with more specialized "embedded" systems.

gadget/		- This is for USB peripheral controller drivers and
		  the various gadget drivers which talk to them.


Individual USB driver directories.  A new driver should be added to the
first subdirectory in the list below that it fits into.

image/		- This is for still image drivers, like scanners or
		  digital cameras.
input/		- This is for any driver that uses the input subsystem,
		  like keyboard, mice, touchscreens, tablets, etc.
media/		- This is for multimedia drivers, like video cameras,
		  radios, and any other drivers that talk to the v4l
		  subsystem.
net/		- This is for network drivers.
serial/		- This is for USB to serial drivers.
storage/	- This is for USB mass-storage drivers.
class/		- This is for all USB device drivers that do not fit
		  into any of the above categories, and work for a range
		  of USB Class specified devices. 
misc/		- This is for all USB device drivers that do not fit
		  into any of the above categories.