This is now set by the usb-serial core, no need for the driver to
individually set it.

Thanks to Alan Stern for the idea to get rid of it.

Cc: William Greathouse <wgreathouse@smva.com>
Cc: Matthias Bruestle and Harald Welte <support@reiner-sct.com>
Cc: Lonnie Mendez <dignome@gmail.com>
Cc: Peter Berger <pberger@brimson.com>
Cc: Al Borchers <alborchers@steinerpoint.com>
Cc: Gary Brubaker <xavyer@ix.netcom.com>
Cc: Oliver Neukum <oliver@neukum.name>
Cc: Matthias Urlichs <smurf@smurf.noris.de>
Cc: Support Department <support@connecttech.com>
Cc: Rusty Russell <rusty@rustcorp.com.au>
Cc: Alan Stern <stern@rowland.harvard.edu>
Cc: Mauro Carvalho Chehab <mchehab@redhat.com>
Cc: Kautuk Consul <consul.kautuk@gmail.com>
Cc: Bill Pemberton <wfp5p@virginia.edu>
Cc: Paul Gortmaker <paul.gortmaker@windriver.com>
Cc: Bart Hartgers <bart.hartgers@gmail.com>
Cc: Johan Hovold <jhovold@gmail.com>
Cc: Preston Fick <preston.fick@silabs.com>
Cc: Uwe Bonnes <bon@elektron.ikp.physik.tu-darmstadt.de>
Cc: Simon Arlott <simon@fire.lp0.eu>
Cc: Andrew Worsley <amworsley@gmail.com>
Cc: "Michał Wróbel" <michal.wrobel@flytronic.pl>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Eric Dumazet <eric.dumazet@gmail.com>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: Felipe Balbi <balbi@ti.com>
Cc: Aleksey Babahin <tamerlan311@gmail.com>
Cc: Dan Carpenter <error27@gmail.com>
Cc: Jiri Kosina <jkosina@suse.cz>
Cc: Donald Lee <donald@asix.com.tw>
Cc: Julia Lawall <julia@diku.dk>
Cc: Michal Sroczynski <msroczyn@gmail.com>
Cc: Wang YanQing <Udknight@gmail.com>
Cc: Dan Williams <dcbw@redhat.com>
Cc: Thomas Tuttle <ttuttle@chromium.org>
Cc: Rigbert Hamisch <rigbert@gmx.de>
Cc: "Rafael J. Wysocki" <rjw@sisk.pl>
Cc: Kuninori Morimoto <kuninori.morimoto.gx@renesas.com>
Cc: Jesper Juhl <jj@chaosbits.net>
Cc: Adhir Ramjiawan <adhirramjiawan0@gmail.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

This is now set by the usb-serial core, no need for the driver to
individually set it.

Thanks to Alan Stern for the idea to get rid of it.

Cc: William Greathouse <wgreathouse@smva.com>
Cc: Matthias Bruestle and Harald Welte <support@reiner-sct.com>
Cc: Lonnie Mendez <dignome@gmail.com>
Cc: Peter Berger <pberger@brimson.com>
Cc: Al Borchers <alborchers@steinerpoint.com>
Cc: Gary Brubaker <xavyer@ix.netcom.com>
Cc: Oliver Neukum <oliver@neukum.name>
Cc: Matthias Urlichs <smurf@smurf.noris.de>
Cc: Support Department <support@connecttech.com>
Cc: Rusty Russell <rusty@rustcorp.com.au>
Cc: Alan Stern <stern@rowland.harvard.edu>
Cc: Mauro Carvalho Chehab <mchehab@redhat.com>
Cc: Kautuk Consul <consul.kautuk@gmail.com>
Cc: Bill Pemberton <wfp5p@virginia.edu>
Cc: Paul Gortmaker <paul.gortmaker@windriver.com>
Cc: Bart Hartgers <bart.hartgers@gmail.com>
Cc: Johan Hovold <jhovold@gmail.com>
Cc: Preston Fick <preston.fick@silabs.com>
Cc: Uwe Bonnes <bon@elektron.ikp.physik.tu-darmstadt.de>
Cc: Simon Arlott <simon@fire.lp0.eu>
Cc: Andrew Worsley <amworsley@gmail.com>
Cc: "Michał Wróbel" <michal.wrobel@flytronic.pl>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Eric Dumazet <eric.dumazet@gmail.com>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: Felipe Balbi <balbi@ti.com>
Cc: Aleksey Babahin <tamerlan311@gmail.com>
Cc: Dan Carpenter <error27@gmail.com>
Cc: Jiri Kosina <jkosina@suse.cz>
Cc: Donald Lee <donald@asix.com.tw>
Cc: Julia Lawall <julia@diku.dk>
Cc: Michal Sroczynski <msroczyn@gmail.com>
Cc: Wang YanQing <Udknight@gmail.com>
Cc: Dan Williams <dcbw@redhat.com>
Cc: Thomas Tuttle <ttuttle@chromium.org>
Cc: Rigbert Hamisch <rigbert@gmx.de>
Cc: "Rafael J. Wysocki" <rjw@sisk.pl>
Cc: Kuninori Morimoto <kuninori.morimoto.gx@renesas.com>
Cc: Jesper Juhl <jj@chaosbits.net>
Cc: Adhir Ramjiawan <adhirramjiawan0@gmail.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

This patch (as1550) fixes a bug in the usb-serial core that affects
the ftdi_sio driver and most likely others as well.  The core
implements suspend and resume routines, but it doesn't store pointers
to those routines in the usb_driver structures that it registers,
even though it does set those drivers' supports_autosuspend flag.  The
end result is that when one of these devices is autosuspended, we try
to call through a NULL pointer.

The patch fixes the problem by setting the suspend and resume method
pointers to the appropriate routines in the USB serial core, along
with the supports_autosuspend field, in each driver as it is
registered.

This should be back-ported to all the stable kernels that have the new
usb_serial_register_drivers() interface.
Signed-off-by: NAlan Stern <stern@rowland.harvard.edu>
Reported-and-tested-by: NFrank Schäfer <schaefer.frank@gmx.net>
Cc: stable <stable@vger.kernel.org>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

The interface data should not be used as a flag to signal disconnect.

Now that all serial drivers use the usb_serial disconnect flag and
mutex, we can set the interface data prior to registering the ports and
there's no need to clear it at disconnect.

This should hopefully also make it more clear that the interface data is
not a flag, which could prevent future misuse.
Signed-off-by: NJohan Hovold <jhovold@gmail.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Fix race between probe and open by making sure that the disconnected
flag is not cleared until all ports have been registered.

A call to tty_open while probe is running may get a reference to the
serial structure in serial_install before its ports have been
registered. This may lead to usb_serial_core calling driver open before
port is fully initialised.

With ftdi_sio this result in the following NULL-pointer dereference as
the private data has not been initialised at open:

[  199.698286] IP: [<f811a089>] ftdi_open+0x59/0xe0 [ftdi_sio]
[  199.698297] *pde = 00000000
[  199.698303] Oops: 0000 [#1] PREEMPT SMP
[  199.698313] Modules linked in: ftdi_sio usbserial
[  199.698323]
[  199.698327] Pid: 1146, comm: ftdi_open Not tainted 3.2.11 #70 Dell Inc. Vostro 1520/0T816J
[  199.698339] EIP: 0060:[<f811a089>] EFLAGS: 00010286 CPU: 0
[  199.698344] EIP is at ftdi_open+0x59/0xe0 [ftdi_sio]
[  199.698348] EAX: 0000003e EBX: f5067000 ECX: 00000000 EDX: 80000600
[  199.698352] ESI: f48d8800 EDI: 00000001 EBP: f515dd54 ESP: f515dcfc
[  199.698356]  DS: 007b ES: 007b FS: 00d8 GS: 0033 SS: 0068
[  199.698361] Process ftdi_open (pid: 1146, ti=f515c000 task=f481e040 task.ti=f515c000)
[  199.698364] Stack:
[  199.698368]  f811a9fe f811a9e0 f811b3ef 00000000 00000000 00001388 00000000 f4a86800
[  199.698387]  00000002 00000000 f806e68e 00000000 f532765c f481e040 00000246 22222222
[  199.698479]  22222222 22222222 22222222 f5067004 f5327600 f5327638 f515dd74 f806e6ab
[  199.698496] Call Trace:
[  199.698504]  [<f806e68e>] ? serial_activate+0x2e/0x70 [usbserial]
[  199.698511]  [<f806e6ab>] serial_activate+0x4b/0x70 [usbserial]
[  199.698521]  [<c126380c>] tty_port_open+0x7c/0xd0
[  199.698527]  [<f806e660>] ? serial_set_termios+0xa0/0xa0 [usbserial]
[  199.698534]  [<f806e76f>] serial_open+0x2f/0x70 [usbserial]
[  199.698540]  [<c125d07c>] tty_open+0x20c/0x510
[  199.698546]  [<c10e9eb7>] chrdev_open+0xe7/0x230
[  199.698553]  [<c10e48f2>] __dentry_open+0x1f2/0x390
[  199.698559]  [<c144bfec>] ? _raw_spin_unlock+0x2c/0x50
[  199.698565]  [<c10e4b76>] nameidata_to_filp+0x66/0x80
[  199.698570]  [<c10e9dd0>] ? cdev_put+0x20/0x20
[  199.698576]  [<c10f3e08>] do_last+0x198/0x730
[  199.698581]  [<c10f4440>] path_openat+0xa0/0x350
[  199.698587]  [<c10f47d5>] do_filp_open+0x35/0x80
[  199.698593]  [<c144bfec>] ? _raw_spin_unlock+0x2c/0x50
[  199.698599]  [<c10ff110>] ? alloc_fd+0xc0/0x100
[  199.698605]  [<c10f0b72>] ? getname_flags+0x72/0x120
[  199.698611]  [<c10e4450>] do_sys_open+0xf0/0x1c0
[  199.698617]  [<c11fcc08>] ? trace_hardirqs_on_thunk+0xc/0x10
[  199.698623]  [<c10e458e>] sys_open+0x2e/0x40
[  199.698628]  [<c144c990>] sysenter_do_call+0x12/0x36
[  199.698632] Code: 85 89 00 00 00 8b 16 8b 4d c0 c1 e2 08 c7 44 24 14 88 13 00 00 81 ca 00 00 00 80 c7 44 24 10 00 00 00 00 c7 44 24 0c 00 00 00 00 <0f> b7 41 78 31 c9 89 44 24 08 c7 44 24 04 00 00 00 00 c7 04 24
[  199.698884] EIP: [<f811a089>] ftdi_open+0x59/0xe0 [ftdi_sio] SS:ESP 0068:f515dcfc
[  199.698893] CR2: 0000000000000078
[  199.698925] ---[ end trace 77c43ec023940cff ]---
Reported-and-tested-by: NKen Huang <csuhgw@gmail.com>
Cc: stable <stable@vger.kernel.org>
Signed-off-by: NJohan Hovold <jhovold@gmail.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

This patch (as1536) fixes a bug in the USB serial core.  Unloading and
reloading a serial driver while a serial device is plugged in causes
errors because of the code in usb_serial_disconnect() that tries to
make sure the port_remove method is called.  With the new order of
driver registration introduced in the 3.4 kernel, this is definitely
not the right thing to do (if indeed it ever was).

The patch removes that whole section code, along with the mechanism
for keeping track of each port's registration state, which is no
longer needed.  The driver core can handle all that stuff for us.

Note: This has been tested only with one or two USB serial drivers.
In theory, other drivers might still run into trouble.  But if they
do, it will be the fault of the drivers, not of this patch -- that is,
the drivers will need to be fixed.
Signed-off-by: NAlan Stern <stern@rowland.harvard.edu>
Reported-and-tested-by: NJohan Hovold <jhovold@gmail.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

All num, magic and owner are set by alloc_tty_driver. No need to
re-set them on each allocation site.

pti driver sets something different to what it passes to
alloc_tty_driver. It is not a bug, since we don't use the lines
parameter in any way. Anyway this is fixed, and now we do the right
thing.
Signed-off-by: NJiri Slaby <jslaby@suse.cz>
Acked-by: NTilman Schmidt <tilman@imap.cc>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

No one uses them anymore, they should be using the safer
usb_serial_register_drivers() and usb_serial_deregister_drivers()
functions instead.

Thanks to Alan Stern for writing these functions and porting all
in-kernel users to them.

Cc: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

This patch (as1522) adds two new routines to the usb-serial core, for
registering and unregistering serial drivers.  Instead of registering
the usb_driver and usb_serial_drivers separately, with error checking
for each one, the drivers can all be registered and unregistered by a
single function call.  This reduces duplicated code.

More importantly, the new core routines change the order in which the
drivers are registered.  Currently the usb-serial drivers are all
registered first and the usb_driver is done last, which leaves a
window for problems.  A udev script may quickly add a new dynamic-ID
for a usb-serial driver, causing the corresponding usb_driver to be
probed.  If the usb_driver hasn't been registered yet then an oops
will occur.

The new routine prevents such problems by registering the usb_driver
first.  To insure that it gets probed properly for already-attached
serial devices, we call driver_attach() after all the usb-serial
drivers have been registered.

Along with adding the new routines, the patch modifies the "generic"
serial driver to use them.  Further patches will similarly modify all
the other in-tree USB serial drivers.
Signed-off-by: NAlan Stern <stern@rowland.harvard.edu>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

But before that we need to reorder the calls so that we don't need to
lower the reference counts if usb_autopm_get_interface fails.
Signed-off-by: NJiri Slaby <jslaby@suse.cz>
Cc: Alan Cox <alan@linux.intel.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

module_param(bool) used to counter-intuitively take an int.  In
fddd5201 (mid-2009) we allowed bool or int/unsigned int using a messy
trick.

It's time to remove the int/unsigned int option.  For this version
it'll simply give a warning, but it'll break next kernel version.
Acked-by: NMauro Carvalho Chehab <mchehab@redhat.com>
Signed-off-by: NRusty Russell <rusty@rustcorp.com.au>

The BKL is a gonner.
Signed-off-by: NDavidlohr Bueso <dave@gnu.org>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>

Use usb_translate_errors() to map USB-specific errors to errors
appropriate for user space (ENOMEM, ENODEV and EIO) in write.

Currently almost all serial drivers simply forward error codes from the
stack (e.g. from usb_submit_urb()), but these codes often have
different meanings in user-space. Doing the mapping in usb-serial core
simplifies driver code and allows for more consistent error reporting.
Signed-off-by: NJohan Hovold <jhovold@gmail.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>

Minor whitespace clean ups.
Signed-off-by: NJohan Hovold <jhovold@gmail.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>

Use usb_translate_errors() to map USB-specific errors to errors
appropriate for user space (ENOMEM, ENODEV and EIO) in open.

Currently almost all serial drivers simply forward error codes from the
stack (e.g. from usb_submit_urb()), but these codes often have
different meanings in user-space. Doing the mapping in usb-serial core
simplifies driver code and allows for more consistent error reporting.
Signed-off-by: NJohan Hovold <jhovold@gmail.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>

Add support for multiple read urbs to generic read implementation.

Use a static array of two read urbs for now which is enough to get a
50% throughput increase in one test setup.
Signed-off-by: NJohan Hovold <jhovold@gmail.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>

Reuse first write urb and bulk-out buffer of the generic write
implementation for drivers that rely on port->write_urb rather than
allocating them separately.
Signed-off-by: NJohan Hovold <jhovold@gmail.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>

Now ${LINUX}/drivers/usb/* can use usb_endpoint_maxp(desc) to get maximum packet size
instead of le16_to_cpu(desc->wMaxPacketSize).
This patch fix it up

Cc: Armin Fuerst <fuerst@in.tum.de>
Cc: Pavel Machek <pavel@ucw.cz>
Cc: Johannes Erdfelt <johannes@erdfelt.com>
Cc: Vojtech Pavlik <vojtech@suse.cz>
Cc: Oliver Neukum <oliver@neukum.name>
Cc: David Kubicek <dave@awk.cz>
Cc: Johan Hovold <jhovold@gmail.com>
Cc: Brad Hards <bhards@bigpond.net.au>
Acked-by: NFelipe Balbi <balbi@ti.com>
Cc: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Cc: Thomas Dahlmann <dahlmann.thomas@arcor.de>
Cc: David Brownell <david-b@pacbell.net>
Cc: David Lopo <dlopo@chipidea.mips.com>
Cc: Alan Stern <stern@rowland.harvard.edu>
Cc: Michal Nazarewicz <m.nazarewicz@samsung.com>
Cc: Xie Xiaobo <X.Xie@freescale.com>
Cc: Li Yang <leoli@freescale.com>
Cc: Jiang Bo <tanya.jiang@freescale.com>
Cc: Yuan-hsin Chen <yhchen@faraday-tech.com>
Cc: Darius Augulis <augulis.darius@gmail.com>
Cc: Xiaochen Shen <xiaochen.shen@intel.com>
Cc: Yoshihiro Shimoda <yoshihiro.shimoda.uh@renesas.com>
Cc: OKI SEMICONDUCTOR, <toshiharu-linux@dsn.okisemi.com>
Cc: Robert Jarzmik <robert.jarzmik@free.fr>
Cc: Ben Dooks <ben@simtec.co.uk>
Cc: Thomas Abraham <thomas.ab@samsung.com>
Cc: Herbert Pötzl <herbert@13thfloor.at>
Cc: Arnaud Patard <arnaud.patard@rtp-net.org>
Cc: Roman Weissgaerber <weissg@vienna.at>
Acked-by: NSarah Sharp <sarah.a.sharp@linux.intel.com>
Cc: Tony Olech <tony.olech@elandigitalsystems.com>
Cc: Florian Floe Echtler <echtler@fs.tum.de>
Cc: Christian Lucht <lucht@codemercs.com>
Cc: Juergen Stuber <starblue@sourceforge.net>
Cc: Georges Toth <g.toth@e-biz.lu>
Cc: Bill Ryder <bryder@sgi.com>
Cc: Kuba Ober <kuba@mareimbrium.org>
Cc: Inaky Perez-Gonzalez <inaky.perez-gonzalez@intel.com>
Signed-off-by: NKuninori Morimoto <kuninori.morimoto.gx@renesas.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>

When a driver doesn't know how much data a device is going to send,
the buffer size should be at least as big as the endpoint's maxpacket
value.  The serial drivers don't follow this rule; many of them
request only 256-byte bulk-in buffers.  As a result, they suffer
overflow errors if a high-speed device wants to send a lot of data,
because high-speed bulk endpoints are required to have a maxpacket
size of 512.

This patch (as1450) fixes the problem by using the driver's
bulk_in_size value as a minimum, always allocating buffers no smaller
than the endpoint's maxpacket size.
Signed-off-by: NAlan Stern <stern@rowland.harvard.edu>
Tested-by: NFlynn Marquardt <flynn@flynnux.de>
CC: <stable@kernel.org> [after .39-rc1 is out]
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>

Only oddities here are a couple of drivers that bogusly called the ldisc
helpers instead of returning -ENOIOCTLCMD. Fix the bug and the rest goes
away.
Signed-off-by: NAlan Cox <alan@linux.intel.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>

We don't use it so we can trim it from here as we try and stamp the file
object dependencies out of the serial code.
Signed-off-by: NAlan Cox <alan@linux.intel.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>

Doing tiocmget was such fun we should do tiocmset as well for the same
reasons
Signed-off-by: NAlan Cox <alan@linux.intel.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>

We don't actually need this and it causes problems for internal use of
this functionality. Currently there is a single use of the FILE * pointer.
That is the serial core which uses it to check tty_hung_up_p. However if
that is true then IO_ERROR is also already set so the check may be removed.
Signed-off-by: NAlan Cox <alan@linux.intel.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>

This patch (as1443) fixes a bug found in many of the USB serial
drivers: They don't set the .usb_driver field in their
usb_serial_driver structure.  This field is needed for assigning
dynamic IDs for device matching.

In addition, starting with the 2.6.37 kernel, the .usb_driver field is
needed for proper autosuspend operation.  Without it, attempts to open
the device file will fail.
Signed-off-by: NAlan Stern <stern@rowland.harvard.edu>
Reported-by: NDan Williams <dcbw@redhat.com>
CC: <stable@kernel.org>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>

This patch (as1437) fixes a bug in the usb-serial autosuspend
handling.  Since the usb-serial core now has autosuspend support, it
must set the .supports_autosuspend member in every serial driver it
registers.  Otherwise the usb_autopm_get_interface() call won't work.

This fixes Bugzilla #23012.
Signed-off-by: NAlan Stern <stern@rowland.harvard.edu>
CC: stable@kernel.org
Reported-by: NKevin Smith <thirdwiggin@gmail.com>
Reported-and-tested-by: NSimon Gerber <gesimu@gmail.com>
Reported-and-tested-by: NMatteo Croce <matteo@openwrt.org>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>

The big kernel lock has been removed from all these files at some point,
leaving only the #include.

Remove this too as a cleanup.
Signed-off-by: NArnd Bergmann <arnd@arndb.de>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Dan Rosenberg noted that various drivers return the struct with uncleared
fields. Instead of spending forever trying to stomp all the drivers that
get it wrong (and every new driver) do the job in one place.

This first patch adds the needed operations and hooks them up, including
the needed USB midlayer and serial core plumbing.
Signed-off-by: NAlan Cox <alan@linux.intel.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>

The patch with title below makes reference count of usb serial module
always more than one after driver is bound.

	USB-BKL: Remove BKL use for usb serial driver probing

In fact, the patch above only replaces lock_kernel() with try_module_get()
, and does not use module_put() to do what unlock_kernel() did, so casue leak
of reference count of usb serial module and the module can not be unloaded
after serial driver is bound with device.

This patch fixes the issue, also simplifies such things:
	-only call try_module_get() once in the entry of usb_serial_probe()
	-only call module_put() once in the exit of usb_serial_probe
Signed-off-by: NMing Lei <tom.leiming@gmail.com>
Cc: Johan Hovold <jhovold@gmail.com>
Cc: Andi Kleen <ak@linux.intel.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>

Usb serial port device is child of its usb interface device, so
we can enable async suspend of usb serial port device to speedup
system suspend.
Signed-off-by: NMing Lei <tom.leiming@gmail.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>

The usb serial driver initialization tried to use the BKL to stop
driver modules from unloading, but that didn't work anyways.

There was already some code to do proper try_module_get,
but it was conditional on having a new probe interface.
I checked all the low level drivers and they all have proper
.owner = THIS_MODULE, so it's ok to always use.

The other problem was the usb_serial_driver_list needing
protection by a lock. This was broken anyways because unregister
did not necessarily have the BKL.

I extended the extending table_lock mutex to protect this case too.

With these changes the BKL can be removed here.
Signed-off-by: NAndi Kleen <ak@linux.intel.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>

Reimplement fifo-based writes in the generic driver using a multiple
pre-allocated urb scheme.

In contrast to multi-urb writes, no allocations (of urbs or buffers) are
made during run-time and there is less pressure on the host stack
queues as currently only two urbs are used (implementation is generic
and can handle more than two urbs as well, though).

Initial tests using ftdi_sio show that the implementation achieves the
same (maximum) throughput at high baudrates as multi-urb writes. The CPU
usage is much lower than for multi-urb writes for small write requests
and only slightly higher for large (e.g. 2k) requests (due to extra copy
via fifo?).

Also outperforms multi-urb writes for small write requests on an
embedded arm-9 system, where multi-urb writes are CPU-bound at high
baudrates (perf reveals that a lot of time is spent in the host stack
enqueue function -- could perhaps be a bug as well).

Keeping the original write_urb, buffer and flag for now as there are
other drivers depending on them.
Signed-off-by: NJohan Hovold <jhovold@gmail.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>

Generalise write buffer preparation.

This allows for drivers to manipulate (e.g. add headers) to bulk out
data before it is sent.

This adds a new function pointer to usb_serial_driver:

int (*prepare_write_buffer)(struct usb_serial_port *port,
		void **dest, size_t size, const void *src, size_t count);

The function is generic and can be used with either kfifo-based or
multi-urb writes:

If *dest is NULL the implementation should allocate dest.
If src is NULL the implementation should use the port write fifo.

If not set, a generic implementation is used which simply uses memcpy or
kfifo_out.
Signed-off-by: NJohan Hovold <jhovold@gmail.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>

Add process_read_urb to usb_serial_driver so that a driver can rely on
the generic read (and throttle) mechanism but still do device specific
processing of incoming data (such as adding tty_flags before pushing to
line discipline).

The default generic implementation handles sysrq for consoles but
otherwise simply pushes to tty.
Signed-off-by: NJohan Hovold <jhovold@gmail.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>

Allow drivers to define custom bulk in/out buffer sizes in struct
usb_serial_driver. If not set, fall back to the default buffer size
which matches the endpoint size.

Three drivers are currently freeing the pre-allocated buffers and
allocating larger ones to achieve this at port probe (ftdi_sio) or even
at port open (ipaq and iuu_phoenix), which needless to say is suboptimal.
Signed-off-by: NJohan Hovold <jhovold@gmail.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>

Replace all instances of using the console variable in struct
usb_serial_port with the struct tty_port version.

CC: Alan Cox <alan@linux.intel.com>
CC: Alan Stern <stern@rowland.harvard.edu>
CC: Oliver Neukum <oliver@neukum.org>
CC: Andrew Morton <akpm@linux-foundation.org>
CC: linux-usb@vger.kernel.org
CC: linux-kernel@vger.kernel.org
Signed-off-by: NJason Wessel <jason.wessel@windriver.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>

We are now refcounted and all the port.count checking is no longer valid
and in fact produces false warnings.
Signed-off-by: NAlan Cox <alan@linux.intel.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>

Fixes confusing "serial_chars_in_buffer = port 0" messages.
Signed-off-by: NJohan Hovold <jhovold@gmail.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>

The USB serial code was a new user of the kfifo API, and it was missed
when porting things to the new kfifo API.

Please make the write_fifo in place.  Here is my patch to fix the
regression and full ported version.
Signed-off-by: NStefani Seibold <stefani@seibold.net>
Reported-and-tested-by: NRafael J. Wysocki <rjw@sisk.pl>
Cc: Greg KH <greg@kroah.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Move the pointer to the spinlock out of struct kfifo.  Most users in
tree do not actually use a spinlock, so the few exceptions now have to
call kfifo_{get,put}_locked, which takes an extra argument to a
spinlock.
Signed-off-by: NStefani Seibold <stefani@seibold.net>
Acked-by: NGreg Kroah-Hartman <gregkh@suse.de>
Acked-by: NMauro Carvalho Chehab <mchehab@redhat.com>
Acked-by: NAndi Kleen <ak@linux.intel.com>
Acked-by: NArnd Bergmann <arnd@arndb.de>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

This is a new generic kernel FIFO implementation.

The current kernel fifo API is not very widely used, because it has to
many constrains.  Only 17 files in the current 2.6.31-rc5 used it.
FIFO's are like list's a very basic thing and a kfifo API which handles
the most use case would save a lot of development time and memory
resources.

I think this are the reasons why kfifo is not in use:

 - The API is to simple, important functions are missing
 - A fifo can be only allocated dynamically
 - There is a requirement of a spinlock whether you need it or not
 - There is no support for data records inside a fifo

So I decided to extend the kfifo in a more generic way without blowing up
the API to much.  The new API has the following benefits:

 - Generic usage: For kernel internal use and/or device driver.
 - Provide an API for the most use case.
 - Slim API: The whole API provides 25 functions.
 - Linux style habit.
 - DECLARE_KFIFO, DEFINE_KFIFO and INIT_KFIFO Macros
 - Direct copy_to_user from the fifo and copy_from_user into the fifo.
 - The kfifo itself is an in place member of the using data structure, this save an
   indirection access and does not waste the kernel allocator.
 - Lockless access: if only one reader and one writer is active on the fifo,
   which is the common use case, no additional locking is necessary.
 - Remove spinlock - give the user the freedom of choice what kind of locking to use if
   one is required.
 - Ability to handle records. Three type of records are supported:
   - Variable length records between 0-255 bytes, with a record size
     field of 1 bytes.
   - Variable length records between 0-65535 bytes, with a record size
     field of 2 bytes.
   - Fixed size records, which no record size field.
 - Preserve memory resource.
 - Performance!
 - Easy to use!

This patch:

Since most users want to have the kfifo as part of another object,
reorganize the code to allow including struct kfifo in another data
structure.  This requires changing the kfifo_alloc and kfifo_init
prototypes so that we pass an existing kfifo pointer into them.  This
patch changes the implementation and all existing users.

[akpm@linux-foundation.org: fix warning]
Signed-off-by: NStefani Seibold <stefani@seibold.net>
Acked-by: NGreg Kroah-Hartman <gregkh@suse.de>
Acked-by: NMauro Carvalho Chehab <mchehab@redhat.com>
Acked-by: NAndi Kleen <ak@linux.intel.com>
Acked-by: NArnd Bergmann <arnd@arndb.de>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>