linux/drivers/usb
Alan Stern 1fb2e05587 USB: EHCI: reorganize isochronous scheduler routine
This patch (as1408) rearranges the scheduling code in ehci-hcd, partly
to improve its structure, but mainly to change the way it works.
Whether or not a transfer exceeds the hardware schedule length will
now be determined by looking at the last frame the transfer would use,
instead of the first available frame following the end of the transfer.

The benefit of this change is that it allows the driver to accept
valid URBs which would otherwise be rejected.  For example, suppose
the schedule length is 1024 frames, the endpoint period is 256 frames,
and a four-packet URB is submitted.  The four transfers would occupy
slots that are 0, 256, 512, and 768 frames past the current frame
(plus an extra slop factor).  These don't exceed the 1024-frame limit,
so the URB should be accepted.  But the current code notices that the
next available slot would be 1024 frames (plus slop) in the future,
which is beyond the limit, and so the URB is rejected unnecessarily.

Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
CC: David Brownell <david-b@pacbell.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2010-08-10 14:35:40 -07:00
..
atm usb: atm: fixed spacing and indentation coding style issues 2010-08-10 14:35:35 -07:00
c67x00 USB: convert usb_hcd bitfields into atomic flags 2010-08-10 14:35:37 -07:00
class USB: usblp: fixed switch, brace, whitespace and spacing coding style issues 2010-08-10 14:35:38 -07:00
core USB: xHCI: Supporting MSI/MSI-X 2010-08-10 14:35:40 -07:00
early echi-dbgp: Add kernel debugger support for the usb debug port 2010-05-20 21:04:31 -05:00
gadget USB: EHCI Debug Port Device Gadget 2010-08-10 14:35:39 -07:00
host USB: EHCI: reorganize isochronous scheduler routine 2010-08-10 14:35:40 -07:00
image USB: BKL removal: mdc800 2010-03-02 14:54:27 -08:00
misc USB: misc: Remove unnecessary casts of private_data 2010-08-10 14:35:39 -07:00
mon USB: mon: kill BKL usage 2010-08-10 14:35:36 -07:00
musb USB: musb: forward debug mode feature to gadget 2010-08-10 14:35:39 -07:00
otg USB: otg/ulpi: extend the generic ulpi driver. 2010-08-10 14:35:40 -07:00
serial USB: io_ti.c: don't return 0 if writing the download record failed 2010-08-10 14:35:40 -07:00
storage usb: storage: freecom: Fixed several coding style issues. 2010-08-10 14:35:39 -07:00
wusbcore fix typos concerning "initiali[zs]e" 2010-06-16 18:05:05 +02:00
Kconfig USB: Add JZ4740 OHCI support 2010-08-05 13:26:19 +01:00
Makefile USB: drivers/usb/Makefile: conditionally descend to 'early' 2010-08-10 14:35:38 -07:00
README
usb-skeleton.c USB: usb-skeleton: Remove unnecessary casts of private_data 2010-08-10 14:35:39 -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.