xHCI host controllers can optionally implement a no-op test.  This
simple test ensures the OS has correctly setup all basic data structures
and can correctly respond to interrupts from the host controller
hardware.

There are two rings exercised by the no-op test:  the command ring, and
the event ring.

The host controller driver writes a no-op command TRB to the command
ring, and rings the doorbell for the command ring (the first entry in
the doorbell array).  The hardware receives this event, places a command
completion event on the event ring, and fires an interrupt.

The host controller driver sees the interrupt, and checks the event ring
for TRBs it can process, and sees the command completion event.  (See
the rules in xhci-ring.c for who "owns" a TRB.  This is a simplified set
of rules, and may not contain all the details that are in the xHCI 0.95
spec.)

A timer fires every 60 seconds to debug the state of the hardware and
command and event rings.  This timer only runs if
CONFIG_USB_XHCI_HCD_DEBUGGING is 'y'.
Signed-off-by: NSarah Sharp <sarah.a.sharp@linux.intel.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>

Instead of keeping a "frame list" like older host controllers, the xHCI
host controller keeps internal representations of the USB devices, with a
transfer ring per endpoint.  The host controller queues Transfer Request
Blocks (TRBs) to the endpoint ring, and then "rings the doorbell" for that
device.  The host controller processes the transfer, places a transfer
completion event on the event ring, and interrupts the system.

The device context base address array must be allocated by the xHCI host
controller driver, along with the device contexts it points to.
Signed-off-by: NSarah Sharp <sarah.a.sharp@linux.intel.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>

Allocate basic xHCI host controller data structures.  For every xHC, there
is a command ring, an event ring, and a doorbell array.

The doorbell array is used to notify the host controller that work has
been enqueued onto one of the rings.  The host controller driver enqueues
commands on the command ring.  The HW enqueues command completion events
on the event ring and interrupts the system (currently using PCI
interrupts, although the xHCI HW will use MSI interrupts eventually).

All rings and the doorbell array must be allocated by the xHCI host
controller driver.

Each ring is comprised of one or more segments, which consists of 16-byte
Transfer Request Blocks (TRBs) that can be chained to form a Transfer
Descriptor (TD) that represents a multiple-buffer request.  Segments are
linked into a ring using Link TRBs, which means they are dynamically
growable.

The producer of the ring enqueues a TD by writing one or more TRBs in the
ring and toggling the TRB cycle bit for each TRB.  The consumer knows it
can process the TRB when the cycle bit matches its internal consumer cycle
state for the ring.  The consumer cycle state is toggled an odd amount of
times in the ring.

An example ring (a ring must have a minimum of 16 TRBs on it, but that's
too big to draw in ASCII art):

              chain  cycle
               bit    bit
 ------------------------
| TD A TRB 1 |  1  |  1  |<-------------  <-- consumer dequeue ptr
 ------------------------               |     consumer cycle state = 1
| TD A TRB 2 |  1  |  1  |              |
 ------------------------               |
| TD A TRB 3 |  0  |  1  |  segment 1   |
 ------------------------               |
| TD B TRB 1 |  1  |  1  |              |
 ------------------------               |
| TD B TRB 2 |  0  |  1  |              |
 ------------------------               |
| Link TRB   |  0  |  1  |-----         |
 ------------------------     |         |
                              |         |
              chain  cycle    |         |
               bit    bit     |         |
 ------------------------     |         |
| TD C TRB 1 |  0  |  1  |<----         |
 ------------------------               |
| TD D TRB 1 |  1  |  1  |              |
 ------------------------               |
| TD D TRB 2 |  1  |  1  |   segment 2  |
 ------------------------               |
| TD D TRB 3 |  1  |  1  |              |
 ------------------------               |
| TD D TRB 4 |  1  |  1  |              |
 ------------------------               |
| Link TRB   |  1  |  1  |-----         |
 ------------------------     |         |
                              |         |
              chain  cycle    |         |
               bit    bit     |         |
 ------------------------     |         |
| TD D TRB 5 |  1  |  1  |<----         |
 ------------------------               |
| TD D TRB 6 |  0  |  1  |              |
 ------------------------               |
| TD E TRB 1 |  0  |  1  |   segment 3  |
 ------------------------               |
|            |  0  |  0  |              | <-- producer enqueue ptr
 ------------------------               |
|            |  0  |  0  |              |
 ------------------------               |
| Link TRB   |  0  |  0  |---------------
 ------------------------
Signed-off-by: NSarah Sharp <sarah.a.sharp@linux.intel.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>

Add PCI initialization code to take control of the xHCI host controller
away from the BIOS, halt, and reset the host controller.  The xHCI spec
says that BIOSes must give up the host controller within 5 seconds.

Add some host controller glue functions to handle hardware initialization
and memory allocation for the host controller.  The current xHCI
prototypes use PCI interrupts, but the xHCI spec requires MSI-X
interrupts.  Add code to support MSI-X interrupts, but use the PCI
interrupts for now.
Signed-off-by: NSarah Sharp <sarah.a.sharp@linux.intel.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>

This is the first of many patches to add support for USB 3.0 devices and
the hardware that implements the eXtensible Host Controller Interface
(xHCI) 0.95 specification.  This specification is not yet publicly
available, but companies can receive a copy by becoming an xHCI
Contributor (see http://www.intel.com/technology/usb/xhcispec.htm).

No xHCI hardware has made it onto the market yet, but these patches have
been tested under the Fresco Logic host controller prototype.

This patch adds the xHCI register sets, which are grouped into five sets:
 - Generic PCI registers
 - Host controller "capabilities" registers (cap_regs) short
 - Host controller "operational" registers (op_regs)
 - Host controller "runtime" registers (run_regs)
 - Host controller "doorbell" registers

These some of these registers may be virtualized if the Linux driver is
running under a VM.  Virtualization has not been tested for this patch.
Signed-off-by: NSarah Sharp <sarah.a.sharp@linux.intel.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>

Steve Holland pointed out that we forgot to call break; in the switch
statment.  This probably resolves a lot of the bug reports I've gotten
for the driver lately.

Stupid me...
Reported-by: NSteve Holland <sdh4@iastate.edu>
Cc: stable <stable@kernel.org>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>

In tests 11 and 12 if the URB completes with an error status (eg babble)
the asynchrous unlink entered an endless loop trying to unlink
a non resubmitted URB.
Signed-off-by: NMartin Fuzzey <mfuzzey@gmail.com>
Acked-by: NDavid Brownell <david-b@pacbell.net>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>

The toggle_bias() function was specified differently for avr32 and at91
architectures. Now, new at91 have the same behavior as avr32.
Consequently, we change to a particular chip function definition: only for
at91sam9rl.
Signed-off-by: NNicolas Ferre <nicolas.ferre@atmel.com>
Acked-by: NHaavard Skinnemoen <haavard.skinnemoen@atmel.com>
Acked-by: NDavid Brownell <dbrownell@users.sourceforge.net>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>

Currently if a laptop is suspended e.g. while docked and then resumed after
undocking it, the following errors get generated because the USB hub in the
docking station and the devices connected to it are no longer available:
pm_op(): usb_dev_resume+0x0/0x10 returns -19
PM: Device 1-2 failed to resume: error -19
pm_op(): usb_dev_resume+0x0/0x10 returns -19
PM: Device 1-2.2 failed to resume: error -19
pm_op(): usb_dev_resume+0x0/0x10 returns -19
PM: Device 1-2.3 failed to resume: error -19

As the removal of USB devices while a system is suspended is a relatively
common use case and in most cases not an error, just return success on
-ENODEV. The user gets informed anyway as the USB subsystem generates
regular disconnect messages for the devices shortly afterwards:
usb 1-2: USB disconnect, address 3
usb 1-2.2: USB disconnect, address 4
usblp0: removed
usb 1-2.3: USB disconnect, address 5
Signed-off-by: NFrans Pop <elendil@planet.nl>
Acked-by: NAlan Stern <stern@rowland.harvard.edu>
Signed-off-by: NRafael J. Wysocki <rjw@sisk.pl>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>

Description:
This driver is used for Intel Langwell* USB OTG controller in Intel
Moorestown* platform. It tries to implement host/device role switch
according to OTG spec.  The actual hsot and device functions are
accomplished in modified EHCI driver and Intel Langwell USB OTG client
controller driver.

* Langwell and Moorestown are names used in development. They are not
  approved official name.

Note:
This patch is the first version Intel Langwell USB OTG Transceiver
driver. The development is not finished, and the bug fixing is on going
for some hardware and software issues. The main purpose of this
submission is for code view.

Supported features:
- Data-line Pulsing SRP
- Support HNP to switch roles
- PCI D0/D3 power management support

Known issues:
- HNP is only tested with another Moorestown platform.
- PCI D0/D3 power management support is not fully tested.
- VBus Pulsing SRP is not support in current version.
Signed-off-by: NHao Wu <hao.wu@intel.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>

Intel Langwell USB Device Controller is a High-Speed USB OTG device
controller in Intel Moorestown platform. It can work in OTG device mode
with Intel Langwell USB OTG transceiver driver as well as device-only
mode. The number of programmable endpoints is different through
controller revision.

NOTE:
This patch is the first version Intel Langwell USB OTG device controller
driver. The bug fixing is on going for some hardware and software
issues.  Intel Langwell USB OTG transceiver driver and EHCI driver
patches will be submitted later.

Supported features:
 - USB OTG protocol support with Intel Langwell USB OTG transceiver
   driver (turn on CONFIG_USB_LANGWELL_OTG)
 - Support control, bulk, interrupt and isochronous endpoints
   (isochronous not tested)
 - PCI D0/D3 power management support
 - Link Power Management (LPM) support

Tested gadget drivers:
 - g_file_storage
 - g_ether
 - g_zero

The passed tests:
 - g_file_storage: USBCV Chapter 9 tests
 - g_file_storage: USBCV MSC tests
 - g_file_storage: from/to host files copying
 - g_ether: ping, ftp and scp files from/to host
 - Hotplug, with and without hubs

Known issues:
 - g_ether: failed part of USBCV chap9 tests
 - LPM support not fully tested

TODO:
 - g_ether: pass all USBCV chap9 tests
 - g_zero: pass usbtest tests
 - Stress tests on different gadget drivers
 - On-chip private SRAM caching support
Signed-off-by: NXiaochen Shen <xiaochen.shen@intel.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>

This patch (as1254) splits up the shutdown method of usb_serial_driver
into a disconnect and a release method.

The problem is that the usb-serial core was calling shutdown during
disconnect handling, but drivers didn't expect it to be called until
after all the open file references had been closed.  The result was an
oops when the close method tried to use memory that had been
deallocated by shutdown.
Signed-off-by: NAlan Stern <stern@rowland.harvard.edu>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>

This patch (as1253) prevents the usb-serial core from calling a
driver's port_probe and port_remove methods more than once per port.
It also removes some unnecessary try_module_get() calls and adds a
missing port_remove method call in a failure path.
Signed-off-by: NAlan Stern <stern@rowland.harvard.edu>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>

Funtions added:
 - setup all the USB audio class device descriptors
 - handle class specific setup request
 - receive data from USB host by ISO transfer
 - play audio data by ALSA sound card
 - open and setup playback PCM interface
 - set default playback PCM parameters
 - provide playback functions for USB audio driver
 - provide PCM parameters set/get functions

Test on:
 - Host: Ubuntu 8.10, kernel 2.6.27
 - Gadget: EZKIT-BF548 with ASoC AD1980 codec

Todo:
 - add real Mute control code
 - add real Volume control code
 - maybe find another way to replace dynamic buffer handling
   with static buffer allocation
 - test on Windows system
 - provide control interface to handle mute/volume control
 - provide capture interface in the future
 - test on BF527, other USB device controler and other audio codec
Signed-off-by: NBryan Wu <cooloney@kernel.org>
Signed-off-by: NMike Frysinger <vapier@gentoo.org>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>

Signed-off-by: NBryan Wu <cooloney@kernel.org>
Signed-off-by: NMike Frysinger <vapier@gentoo.org>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>

Driver support for the new high-speed/OtG block that is
in the newer line of Samsung SoC devices such as the
S3C64XX series.

This driver does not currntly have DMA support enabled due
to issues with buffer alignment which need to be sorted out.
Signed-off-by: NBen Dooks <ben@simtec.co.uk>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>

This patch adds support for i.MX3x (only tested with i.MX31 so far) ARM
SoCs to the fsl_usb2_udc driver. It also moves PHY configuration before
controller reset, because otherwise an ULPI PHY doesn't get a reset and
doesn't function after a reboot. The problem with longer control transfers
is still not fixed. The patch renames the fsl_usb2_udc.c file to
fsl_udc_core.c to preserve the same module name for user-space
backwards compatibility.
Signed-off-by: NGuennadi Liakhovetski <lg@denx.de>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>

The only time a sysrq should get processed is if the attached device
is a console.  This is intended to protect sysrq execution on a host
connected with a terminal program.

Here is the problem scenario:

host A <-- rs232 link --> host B

Host A is using mincom and a usb pl2303 device to connect to host b
which is a linux system with a usb pl2303 device acting as the serial
console.  When host B is rebooted the pl2303 emits random junk
characters on reset.  These character sequences contain serial break
signals most of the time and when translated to a sysrq have caused
host A to get random processes killed, reboots or power down.

It is true that in this setup with this patch host B might still have
the same problem as host A if you reboot host A.  In most cases host A
is a development host which seldom gets rebooted, and you could turn
off sysrq temporarily on host B if you need to reboot host A.
Signed-off-by: NJason Wessel <jason.wessel@windriver.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>

Add callbacks to process the sysrq when using a pl2303 usb device as a
console.
Signed-off-by: NJason Wessel <jason.wessel@windriver.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>

This patch fixes a bug in the RNDIS code.

Due to this bug gether_connect() fails as the port remains un-initialized.

As a result following USB Compliance Tests were failing.
(1)EndpointDescriptorTest_DeviceConfigured
(2)Interface Descriptor Test.
(3)Halt Endpoint Test.
(4)SetConfigurationTest

The fix aligns rndis code with the CDC ECM for xxx_set_alt().

The above listed USB Compliance test passes with this fix.

Tested working fine on SDP with OMAP 3430.
Signed-off-by: NMaulik Mankad <x0082077@ti.com>
CC: David Brownell <david-b@pacbell.net>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>

This mobile phone fails to work as a modem, failing with:
 cdc_acm: Zero length descriptor references
 cdc_acm: probe of 1-6.1.3:1.1 failed with error -22

Tested to work fine with this patch.
Signed-off-by: NKir Kolyshkin <kir@openvz.org>
Cc: stable <stable@kernel.org>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>

When a zero-length packet has been requested and another packet is
written into the fifo, the MX1 tends to send the first byte of the
previous packet instead of the first byte of the current packet.
The CRC is adjusted accordingly so that this packet is _not_
discarded by the host.

Waiting for the ZLPS bit to clear avoids these bad packets.
Signed-off-by: NDaniel Glöckner <dg@emlix.com>
Cc: Darius Augulis <augulis.darius@gmail.com>
Cc: David Brownell <dbrownell@users.sourceforge.net>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>

Some usb serial host drivers expect a short packet before they forward
the data to the application. This is caused by them trying to read more
than one packet at a time. So when the gadget sends an exact multiple
of the maximum packet size, it should append a zero-length packet.
Signed-off-by: NDaniel Glöckner <dg@emlix.com>
Cc: David Brownell <dbrownell@users.sourceforge.net>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>

This replaces dma_sync_single() and dma_sync_sg() with
dma_sync_single_for_cpu() and dma_sync_sg_for_cpu() respectively
because they is an obsolete API; include/linux/dma-mapping.h says:

/* Backwards compat, remove in 2.7.x */
#define dma_sync_single		dma_sync_single_for_cpu
#define dma_sync_sg		dma_sync_sg_for_cpu
Signed-off-by: NFUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>

This patch (as1245) fixes a bug in ehci-hcd.  When an URB is queued
for an endpoint whose QH is already in the LINKED state, the QH
doesn't get refreshed.  As a result, if usb_clear_halt() was called
during the time that the QH was linked but idle, the data toggle value
in the QH doesn't get reset.

The symptom is that after a clear_halt, data gets lost and transfers
time out.  This problem is starting to show up now because the
"ehci-hcd unlink speedups" patch causes QHs with no queued URBs to
remain linked for a suitable time.

The patch utilizes the new endpoint_reset mechanism to fix the
problem.  When an endpoint is reset, the new method forcibly unlinks
the QH (if necessary) and safely updates the toggle value.  This
allows qh_update() to be simplified and avoids using usb_device's
toggle bits in a rather unintuitive way.
Signed-off-by: NAlan Stern <stern@rowland.harvard.edu>
CC: David Brownell <david-b@pacbell.net>
Tested-by: NDavid <david@unsolicited.net>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>

CPU/board specific parameters (PLL clock, vif etc...) can be set
by platform_data instead of module_param.

v2: remove irq_sense member in platform_data because it can OR in
    IRQF_TRIGGER_LOW or IRQF_TRIGGER_FALLING against IORESOURCE_IRQ in
    the struct resource.
Signed-off-by: NYoshihiro Shimoda <shimoda.yoshihiro@renesas.com>
Reviewed-by: NPaul Mundt <lethal@linux-sh.org>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>

Some unusual usb devices from the maker "Option" are switched from
storage to serial/modem mode by sending a SCSI REZERO command. In one
case a fairly common vendor/device ID is affected which led to problems
for users of other modems or phones which are not supposed to be
switched.

The patch adds a filter by reading the vendor name with the SCSI INQUIRY
command, and skips the switching code for all unrecognized entries.

Further changes are cleanups and corrections pointed out by Alan Stern.

Tested with two devices with the IDs 05c6:1000, one from "Option" and
switchable, and one from Samsung (cell phone).
Signed-off-by: NJosua Dietze <digidietze@draisberghof.de>
Acked-by: NAlan Stern <stern@rowland.harvard.edu>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>

This patch (as1243) tries to improve ehci-hcd's scheduling of
interrupt transfers.  Instead of trying to cram all transfers with the
same period into the same frame, the new code will spread the
transfers out among lots of different frames.  This should reduce the
periodic schedule load in any one frame -- some host controllers have
trouble when there's too much work to do.

A more thorough approach would stagger the uframe values as well.  But
this is enough to make a big improvement.
Signed-off-by: NAlan Stern <stern@rowland.harvard.edu>
Tested-by: NDwayne Fontenot <dwayne.fontenot@att.net>
Cc: David Brownell <david-b@pacbell.net>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>

This patch (as1242) fixes the return values from the special
init functions in usb-storage.  They are supposed to return 0 for
success, not USB_STOR_TRANSPORT_GOOD.
Signed-off-by: NAlan Stern <stern@rowland.harvard.edu>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>

Omap3 MUSB AUTOIDLE functionality configured through OTG_SYSCONFIG
register prevents the device from going into retention.
This is a workaround (by Richard Woodruff/TI), as his comment :
> A new MUSB bug which is a match to data below was identified very
> recently (on hardware and in simulation).
> This bug is in 3430 and not 3630.
> As a priority test (and as new default) you should have engineers
> disable autoidle for MUSB block.
> This is the workaround which will show up in next errata.
Signed-off-by: NNiilo Minkkinen <ext-niilo.1.minkkinen@nokia.com>
Signed-off-by: NRichard Woodruff <r-woodruff2@ti.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>

This implement support in cdc-acm for acm devices another popular OS can handle

- adds support for autodetection of devices that use one interface
- autodetection of endpoints
- add a quirk for surpressing a setting that OS doesn't use
- autoassume that quirk for single interface devices
Signed-off-by: NOliver Neukum <oliver@neukum.org>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>

drivers/usb/serial/sierra.c: In function 'sierra_write':
drivers/usb/serial/sierra.c:375: warning: format '%d' expects type 'int', but argument 5 has type 'size_t'
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Cc: Elina Pasheva <epasheva@sierrawireless.com>
Cc: Rory Filer <rfiler@SierraWireless.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>

cppcheck found another leak in drivers/usb/gadget/imx_udc.c

Cc: Mike Lee <eemike@gmail.com>
Cc: Darius Augulis <augulis.darius@gmail.com>
Signed-off-by: NDaniel Mack <daniel@caiaq.de>
Cc: David Brownell <david-b@pacbell.net>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>

The endpoint devices look like simple attribute groups now, and no longer
like devices with a specific subsystem. They will also no longer emit uevents.

It also removes the device node requests for endpoint devices, which are not
implemented for now.
Signed-off-by: NKay Sievers <kay.sievers@vrfy.org>
Acked-by: NAlan Stern <stern@rowland.harvard.edu>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>

- Removed potential kernel oops from sierra_calc_num_ports() function.
  Calling this function twice would likely have caused an oops because
  the function releases allocated memory after the first call.
- Modified sierra_probe() function to reflect the changes in
  sierra_calc_num_ports().
Signed-off-by: NElina Pasheva <epasheva@sierrawireless.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>

- Fixed a problem when re-submitting urb from interrupt callback in
  function sierra_instat_callback(). This suppresses also issuing of
  error messages in /var/log/kern.log
- Removed redundant debug message at the beginning of
  sierra_instat_callback() function
- Changed a debug message to be an error message
Signed-off-by: NElina Pasheva <epasheva@sierrawireless.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>

- Fixed a problem with transferring packets with size a multiple of Bulk
  Xfer size in function sierra_write(). Added transfer flag
  URB_ZERO_PACKET before submitting the urb to trigger Zero-length data
  transfer when packet size is a multiple of Bulk Xfer.
Signed-off-by: NElina Pasheva <epasheva@sierrawireless.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>

Change driver to make use of the new functions in
include/linux/usb/serial.h so as to allow the driver to handle the
sysrq
Signed-off-by: NJason Wessel <jason.wessel@windriver.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>

The usb_debug driver was modified to implement serial break handling
by using a "magic" data packet comprised of the sequence:

       0x00 0xff 0x01 0xfe   0x00 0xfe 0x01 0xff

When the tty layer requests a serial break the usb_debug driver sends
the magic packet.  On the receiving side the magic packet is thrown
away or a sysrq is activated depending on what kernel .config options
have been set.

The generic serial driver was modified as well as the usb serial
headers to generically implement sysrq processing in the same way the
non usb uart based drivers implement the sysrq handling.  This will
allow other usb serial devices to implement sysrq handling as desired.

The new usb serial functions are named similarly and implemented
similarly to the uart functions as follows:

usb_serial_handle_break <-> uart_handle_break
usb_serial_handle_sysrq_char <-> uart_handle_sysrq_char
Signed-off-by: NJason Wessel <jason.wessel@windriver.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>

Alan Stern commented that the private driver counts must be updated
regard less of the status return on the urb when the write call back
is executed.

This patch alters the behavior to update the private driver counts by
simply moving the status check to after the driver count update.
Signed-off-by: NJason Wessel <jason.wessel@windriver.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>