Commit Graph

133 Commits

Author SHA1 Message Date
Ming Lei
d92a3ca689 USB: serial: fix leak of usb serial module refrence count
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: Ming Lei <tom.leiming@gmail.com>
Cc: Johan Hovold <jhovold@gmail.com>
Cc: Andi Kleen <ak@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2010-08-23 20:50:15 -07:00
Ming Lei
a7a6b79bc5 USB: serial: enable async suspend for usb serial port device
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: Ming Lei <tom.leiming@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2010-08-10 14:35:39 -07:00
Andi Kleen
0daeed381c USB-BKL: Remove BKL use for usb serial driver probing
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: Andi Kleen <ak@linux.intel.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2010-08-10 14:35:36 -07:00
Johan Hovold
27c7acf220 USB: serial: reimplement generic fifo-based writes
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: Johan Hovold <jhovold@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2010-05-20 13:21:42 -07:00
Johan Hovold
eaa3bcb06a USB: serial: generalise write buffer preparation
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: Johan Hovold <jhovold@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2010-05-20 13:21:35 -07:00
Johan Hovold
2315432064 USB: serial: generalise generic read implementation
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: Johan Hovold <jhovold@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2010-05-20 13:21:34 -07:00
Johan Hovold
bbcb2b9074 USB: serial: allow drivers to define bulk buffer sizes
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: Johan Hovold <jhovold@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2010-05-20 13:21:33 -07:00
Jason Wessel
bd5afa9eac usb-serial: Use tty_port version console instead of usb_serial_port
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: Jason Wessel <jason.wessel@windriver.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2010-05-20 13:21:31 -07:00
Alan Cox
49d3380e3f tty: Fix various bogus WARN checks in the usb serial layer
We are now refcounted and all the port.count checking is no longer valid
and in fact produces false warnings.

Signed-off-by: Alan Cox <alan@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2010-03-02 14:55:02 -08:00
Johan Hovold
b4fc2aeef2 USB: serial: fix typo in debug message
Fixes confusing "serial_chars_in_buffer = port 0" messages.

Signed-off-by: Johan Hovold <jhovold@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2010-03-02 14:53:03 -08:00
Stefani Seibold
119eecc831 Fix usb_serial_probe() problem introduced by the recent kfifo changes
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: Stefani Seibold <stefani@seibold.net>
Reported-and-tested-by: Rafael 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: Linus Torvalds <torvalds@linux-foundation.org>
2009-12-23 08:53:31 -08:00
Stefani Seibold
c1e13f2567 kfifo: move out spinlock
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: Stefani Seibold <stefani@seibold.net>
Acked-by: Greg Kroah-Hartman <gregkh@suse.de>
Acked-by: Mauro Carvalho Chehab <mchehab@redhat.com>
Acked-by: Andi Kleen <ak@linux.intel.com>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-12-22 14:17:56 -08:00
Stefani Seibold
4546548789 kfifo: move struct kfifo in place
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: Stefani Seibold <stefani@seibold.net>
Acked-by: Greg Kroah-Hartman <gregkh@suse.de>
Acked-by: Mauro Carvalho Chehab <mchehab@redhat.com>
Acked-by: Andi Kleen <ak@linux.intel.com>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-12-22 14:17:55 -08:00
Alan Cox
82fc594343 usb_serial: Kill port mutex
The tty port has a port mutex used for all the port related locking so we
don't need the one in the USB serial layer any more.

Signed-off-by: Alan Cox <alan@linux.intel.com>
Cc: Alan Stern <stern@rowland.harvard.edu>
Cc: Oliver Neukum <oliver@neukum.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2009-12-11 15:18:04 -08:00
Alan Cox
e1108a63e1 usb_serial: Use the shutdown() operation
As Alan Stern pointed out - now we have tty_port_open the shutdown method
and locking allow us to whack the other bits into the full helper methods
and provide a shutdown op which the tty port code will synchronize with 
setup for us.

Signed-off-by: Alan Cox <alan@linux.intel.com>
Cc: Alan Stern <stern@rowland.harvard.edu>
Cc: Oliver Neukum <oliver@neukum.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2009-12-11 15:18:04 -08:00
Alan Cox
64bc397914 tty_port: add "tty_port_open" helper
For the moment this just moves the USB logic over and fixes the 'what if
we open and hangup at the same time' race noticed by Oliver Neukum.

Signed-off-by: Alan Cox <alan@linux.intel.com>
Cc: Alan Stern <stern@rowland.harvard.edu>
Cc: Oliver Neukum <oliver@neukum.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2009-12-11 15:18:04 -08:00
Oliver Neukum
a5f6005d7b USB: small fix in error case of suspend in generic usbserial code
usb:usbserial: fix flags in error case of suspension

suspended flag must be reset in error case

Signed-off-by: Oliver Neukum <oliver@neukum.org>
Cc: stable <stable@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2009-10-09 13:52:08 -07:00
Alan Stern
a4720c650b USB: serial: don't call release without attach
This patch (as1295) fixes a recently-added bug in the USB serial core.
If certain kinds of errors occur during probing, the core may call a
serial driver's release method without previously calling the attach
method.  This causes some drivers (io_ti in particular) to perform an
invalid memory access.

The patch adds a new flag to keep track of whether or not attach has
been called.

Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Tested-by: Jean-Denis Girard <jd.girard@sysnux.pf>
CC: stable <stable@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2009-10-09 13:52:05 -07:00
Dave Young
f278a2f7bb tty: Fix regressions caused by commit b50989dc
The following commit made console open fails while booting:

	commit b50989dc44
	Author: Alan Cox <alan@linux.intel.com>
	Date:   Sat Sep 19 13:13:22 2009 -0700

	tty: make the kref destructor occur asynchronously

Due to tty release routines run in a workqueue now, error like the
following will be reported while booting:

INIT open /dev/console Input/output error

It also causes hibernation regression to appear as reported at
http://bugzilla.kernel.org/show_bug.cgi?id=14229

The reason is that now there's latency issue with closing, but when
we open a "closing not finished" tty, -EIO will be returned.

Fix it as per the following Alan's suggestion:

  Fun but it's actually not a bug and the fix is wrong in itself as
  the port may be closing but not yet being destructed, in which case
  it seems to do the wrong thing.  Opening a tty that is closing (and
  could be closing for long periods) is supposed to return -EIO.

  I suspect a better way to deal with this and keep the old console
  timing is to split tty->shutdown into two functions.

  tty->shutdown() - called synchronously just before we dump the tty
  onto the waitqueue for destruction

  tty->cleanup() - called when the destructor runs.

  We would then do the shutdown part which can occur in IRQ context
  fine, before queueing the rest of the release (from tty->magic = 0
  ...  the end) to occur asynchronously

  The USB update in -next would then need a call like

       if (tty->cleanup)
               tty->cleanup(tty);

  at the top of the async function and the USB shutdown to be split
  between shutdown and cleanup as the USB resource cleanup and final
  tidy cannot occur synchronously as it needs to sleep.

  In other words the logic becomes

       final kref put
               make object unfindable

       async
               clean it up

Signed-off-by: Dave Young <hidave.darkstar@gmail.com>
[ rjw: Rebased on top of 2.6.31-git, reworked the changelog. ]
Signed-off-by: "Rafael J. Wysocki" <rjw@sisk.pl>
[ Changed serial naming to match new rules, dropped tty_shutdown as per
  comments from Alan Stern  - Linus ]
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-09-27 13:35:16 -07:00
David VomLehn
8e8dce0650 USB: use kfifo to buffer usb-generic serial writes
When do_output_char() attempts to write a carriage return/line feed sequence,
it first checks to see how much buffer room is available. If there are at least
two characters free, it will write the carriage return/line feed with two calls
to tty_put_char(). It calls the tty_operation functions write() for devices that
don't support the tty_operations function put_char(). If the USB generic serial
device's write URB is not in use, it will return the buffer size when asked how
much room is available. The write() of the carriage return will cause it to mark
the write URB busy, so the subsequent write() of the line feed will be ignored.

This patch uses the kfifo infrastructure to implement a write FIFO that
accurately returns the amount of space available in the buffer.

Signed-off-by: David VomLehn <dvomlehn@cisco.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2009-09-23 06:46:34 -07:00
Oliver Neukum
81e5b23cd2 USB: fix wrong order of events in usb serial suspension
if a subdriver has an additional suspend method, it must be called
first to allow the subdriver to return -EBUSY, because the second
half cannot be easily undone.

Signed-off-by: Oliver Neukum <oliver@neukum.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2009-09-23 06:46:29 -07:00
Jiri Slaby
75b48f09e5 USB: usb-serial, remove unused variables
There are some unused variables in serial_do_down. Remove them.

Signed-off-by: Jiri Slaby <jirislaby@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2009-09-23 06:46:26 -07:00
Alan Stern
320348c8d5 usb-serial: straighten out serial_open
This patch (as1291) removes a bunch of code from serial_open(), things
that were rendered unnecessary by earlier patches.  A missing spinlock
is added to protect port->port.count, which needs to be incremented
even if the open fails but not if the tty has gotten a hangup.  The
test for whether the hardware has been initialized, based on the use
count, is replaced by a more transparent test of the
ASYNCB_INITIALIZED bit in the port flags.

Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Cc: stable <stable@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2009-09-19 13:13:42 -07:00
Alan Stern
ff8324df11 usb-serial: add missing tests and debug lines
This patch (as1290) adds some missing tests.  serial_down() isn't
supposed to do anything if the hardware hasn't been initialized, and
serial_close() isn't supposed to do anything if the tty has gotten a
hangup (because serial_hangup() takes care of shutting down the
hardware).

The patch also updates and adds a few debugging lines.

Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Cc: stable <stable@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2009-09-19 13:13:41 -07:00
Alan Stern
74556123e0 usb-serial: rename subroutines
This patch (as1289) renames serial_do_down() to serial_down() and
serial_do_free() to serial_release().  It also adds a missing call to
tty_shutdown() in serial_release().

Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Cc: stable <stable@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2009-09-19 13:13:41 -07:00
Alan Stern
7e29bb4b77 usb-serial: fix termios initialization logic
This patch (as1288) fixes the initialization logic in
serial_install().  A new tty always needs to have a termios
initialized no matter what, not just in the case where the lower
driver will override the termios settings.

Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Cc: stable <stable@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2009-09-19 13:13:40 -07:00
Alan Stern
cc56cd0157 usb-serial: acquire references when a new tty is installed
This patch (as1287) makes serial_install() be reponsible for acquiring
references to the usb_serial structure and the driver module when a
tty is first used.  This is more sensible than having serial_open() do
it, because a tty can be opened many times whereas it is installed
only once, when it is created.  (Not to mention that these actions are
reversed when the tty is released, not when it is closed.)  Finally,
it is at install time that the TTY core takes its own reference to the
usb_serial module, so it is only fitting that we should act the same
way in regard to the lower-level serial driver.

Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Cc: stable <stable@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2009-09-19 13:13:40 -07:00
Alan Stern
8bc2c1b2da usb-serial: change logic of serial lookups
This patch (as1286) changes usb_serial_get_by_index().  Now the
routine will check whether the serial device has been disconnected; if
it has then the return value will be NULL.  If the device hasn't been
disconnected then the routine will return with serial->disc_mutex
held, so that the caller can use the structure without fear of racing
against driver unloads.

This permits the scope of table_mutex in destroy_serial() to be
reduced.  Instead of protecting the entire function, it suffices to
protect the part that actually uses serial_table[], i.e., the call to
return_serial().  There's no longer any danger of the refcount being
incremented after it reaches 0 (which was the reason for having the
large scope previously), because it can't reach 0 until the serial
device has been disconnected.

Also, the patch makes serial_install() check that serial is non-NULL
before attempting to use it.

Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Cc: stable <stable@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2009-09-19 13:13:40 -07:00
Alan Stern
f5b0953a89 usb-serial: put subroutines in logical order
This patch (as1285) rearranges the subroutines in usb-serial.c
concerned with tty lifetimes into a more logical order: install, open,
hangup, close, release.  It also updates the formatting of the
kerneldoc comments.

Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Cc: stable <stable@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2009-09-19 13:13:39 -07:00
Alan Stern
41bd34ddd7 usb-serial: change referencing of port and serial structures
This patch (as1284) changes the referencing of the usb_serial and
usb_serial_port structures in usb-serial.c.  It's not feasible to make
the port structures keep a reference to the serial structure, because
the ports need to remain in existence when serial is released -- quite
a few of the drivers expect this.  Consequently taking a reference
to the port when the device file is open is insufficient; such a
reference would not pin serial.

To fix this, we now take a reference to serial when the device file is
opened.  The final put_device() for the ports occurs in
destroy_serial(), so that the ports will last as long as they are
needed.

The patch initializes all the port devices, including those in the
unused "fake" ports.  This makes the code more uniform because they
can all be released in the same way.  The error handling code in
usb_serial_probe() is much simplified by this approach; instead of
freeing everything by hand we can use a single usb_serial_put() call.

Also simplified is the port-release mechanism.  Instead of being two
separate routines, port_release() and port_free() can be combined into
one.

Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Cc: stable <stable@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2009-09-19 13:13:39 -07:00
Alan Cox
fe1ae7fdd2 tty: USB serial termios bits
Various drivers have hacks to mangle termios structures. This stems from
the fact there is no nice setup hook for configuring the termios settings
when the port is created

Signed-off-by: Alan Cox <alan@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2009-09-19 13:13:33 -07:00
Alan Cox
a509a7e478 tty: USB does not need the filp argument in the drivers
And indeed none of them use it. Clean this up as it will make moving to a
standard open method rather easier.

Signed-off-by: Alan Cox <alan@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2009-09-19 13:13:26 -07:00
Alan Cox
4455e34495 tty: USB can now use the shutdown method for kref based freeing of ports
Signed-off-by: Alan Cox <alan@linux.intel.com>
Cc: stable <stable@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2009-09-19 13:13:24 -07:00
Alan Cox
d2b391822a tty: USB hangup is racy
The USB layer uses tty_hangup to deal with unplugs of the physical hardware
(analogous to loss of carrier) and then frees the resources. However the
tty_hangup is asynchronous. As the hangup can sleep we can use tty_vhangup
which is the non async version to avoid freeing resources too early.

Signed-off-by: Alan Cox <alan@linux.intel.com>
Cc: stable <stable@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2009-09-19 13:13:23 -07:00
Alan Cox
c56d300086 usb_serial: Fix remaining ref count/lock bugs
This fixes
- locking bug that was hidden by ecc2e05e73
- Regression #13821
- Spurious warning when closing and blocking for data write out

With these changes my PL2303 always ends up as ttyUSB0 when it should and
the module refcounts stay correct.

I'll do a more wholesale split & tidy of _open in the next release or two
as we get a standard tty_port_open and port->ops->init port->ops->shutdown
call backs.

Copy sent to Alan Stern and Carlos Mafra just to confirm it fixes all the
reports but it passes local testing with the same hardware as Alan Stern.

Signed-off-by: Alan Cox <alan@linux.intel.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-07-27 17:26:23 -07:00
Alan Cox
b68f2fb9e7 tty: Fix a USB serial crash/scribble
The port lock is used to protect the port state. However the port structure
is freed on a hangup, then the lock taken on a close. The right fix is to
drop the port on tty->shutdown() but we can't yet do that due to sleep v
non-sleeping rules. Instead do the next best thing and fix it up when we are
not in -rc season.

Reported-by: Daniel Mack <daniel@caiaq.de>
Signed-off-by: Alan Cox <alan@linux.intel.com>
Tested-by: Daniel Mack <daniel@caiaq.de>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-07-27 12:23:22 -07:00
Linus Torvalds
51feb98d25 Merge git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb-2.6
* git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb-2.6: (48 commits)
  USB: otg: fix module reinsert issue
  USB: handle zero-length usbfs submissions correctly
  USB: EHCI: report actual_length for iso transfers
  USB: option: remove unnecessary and erroneous code
  USB: cypress_m8: remove invalid Clear-Halt
  USB: musb_host: undo incorrect change in musb_advance_schedule()
  USB: fix LANGID=0 regression
  USB: serial: sierra driver id_table additions
  USB serial: Add ID for Turtelizer, an FT2232L-based JTAG/RS-232 adapter.
  USB: fix race leading to a write after kfree in usbfs
  USB: Sierra: fix oops upon device close
  USB: option.c: add A-Link 3GU device id
  USB: Serial: Add support for Arkham Technology adapters
  USB: Fix option_ms regression in 2.6.31-rc2
  USB: gadget audio: select SND_PCM
  USB: ftdi: support NDI devices
  Revert USB: usbfs: deprecate and hide option for !embedded
  USB: usb.h: fix kernel-doc notation
  USB: RNDIS gadget, fix issues talking from PXA
  USB: serial: FTDI with product code FB80 and vendor id 0403
  ...
2009-07-13 10:23:03 -07:00
Jason Wessel
6e40612101 USB: console: Fix regression in usb console on kernel boot
The commit 335f8514f2 introduced a
regression which stopped usb consoles from working correctly as a
kernel boot console as well as interactive login device.

The addition of the serial_close() which in turn calls
tty_port_close_start() will change the reference count of port.count
and warn about it.  The usb console code had previously incremented
the port.count to indicate it was making use of the device as a
console and the forced change causes a double open on the usb device
which leads to a non obvious kernel oops later on when the tty is
freed.

To fix the problem instead make use of port->console to track if the
port is in fact an active console port to avoid double initialization
of the usb serial device.  The port.count is incremented and
decremented only with in the scope of usb_console_setup() for the
purpose of the low level driver initialization.

Signed-off-by: Jason Wessel <jason.wessel@windriver.com>
Acked-by: Alan Cox <alan@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2009-07-12 15:16:39 -07:00
Alexey Dobriyan
405f55712d headers: smp_lock.h redux
* Remove smp_lock.h from files which don't need it (including some headers!)
* Add smp_lock.h to files which do need it
* Make smp_lock.h include conditional in hardirq.h
  It's needed only for one kernel_locked() usage which is under CONFIG_PREEMPT

  This will make hardirq.h inclusion cheaper for every PREEMPT=n config
  (which includes allmodconfig/allyesconfig, BTW)

Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-07-12 12:22:34 -07:00
Thadeu Lima de Souza Cascardo
f4fa446883 usb_serial: Fix oops when unexisting usb serial device is opened.
This commit 335f8514f2 has stopped
properly checking if there is any usb serial associated with the tty in
the close function. It happens the close function is called by releasing
the terminal right after opening the device fails.

As an example, open fails with a non-existing device, when probe has
never been called, because the device has never been plugged. This is
common in systems with static modules and no udev.

Signed-off-by: Thadeu Lima de Souza Cascardo <cascardo@holoscopio.com>
Signed-off-by: Alan Cox <alan@linux.intel.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-06-25 11:24:26 -07:00
Alan Stern
f9c99bb8b3 USB: usb-serial: replace shutdown with disconnect, release
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: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2009-06-15 21:44:47 -07:00
Alan Stern
c706ebdfc8 USB: usb-serial: call port_probe and port_remove at the right times
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: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2009-06-15 21:44:47 -07:00
Alan Cox
335f8514f2 tty: Bring the usb tty port structure into more use
This allows us to clean stuff up, but is probably also going to cause
some app breakage with buggy apps as we now implement proper POSIX behaviour
for USB ports matching all the other ports. This does also mean other apps
that break on USB will now work properly.

Signed-off-by: Alan Cox <alan@lxorguk.ukuu.org.uk>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-06-11 08:50:56 -07:00
Alan Stern
0a3c8549ea usb-serial: fix crash when sub-driver updates firmware
This patch (as1244) fixes a crash in usb-serial that occurs when a
sub-driver returns a positive value from its attach method, indicating
that new firmware was loaded and the device will disconnect and
reconnect.  The usb-serial core then skips the step of registering the
port devices; when the disconnect occurs, the attempt to unregister
the ports fails dramatically.

This problem shows up with Keyspan devices and it might affect others
as well.

When the attach method returns a positive value, the patch sets
num_ports to 0.  This tells usb_serial_disconnect() not to try
unregistering any of the ports; instead they are cleaned up by
destroy_serial().

Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Tested-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: stable <stable@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2009-05-28 13:54:43 -07:00
Alan Stern
2d93148ab6 USB: serial: fix lifetime and locking problems
This patch (as1229) fixes a few lifetime and locking problems in the
usb-serial driver.  The main symptom is that an invalid kevent is
created when the serial device is unplugged while a connection is
active.

	Ports should be unregistered when device is disconnected,
	not when the parent usb_serial structure is deallocated.

	Each open file should hold a reference to the corresponding
	port structure, and the reference should be released when
	the file is closed.

	serial->disc_mutex should be acquired in serial_open(), to
	resolve the classic race between open and disconnect.

	serial_close() doesn't need to hold both serial->disc_mutex
	and port->mutex at the same time.

	Release the subdriver's module reference only after releasing
	all the other references, in case one of the release routines
	needs to invoke some code in the subdriver module.

	Replace a call to flush_scheduled_work() (which is prone to
	deadlocks) with cancel_work_sync().  Also, add a call to
	cancel_work_sync() in the disconnect routine.

	Reduce the scope of serial->disc_mutex in serial_disconnect().
	The only place it really needs to protect is where the
	"disconnected" flag is set.

This fixes the bug reported in

	http://bugs.freedesktop.org/show_bug.cgi?id=20703

Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Tested-by: Dan Williams <dcbw@redhat.com>
Tested-by: Ming Lei <tom.leiming@gmail.com>
Reviewed-by: Oliver Neukum <oliver@neukum.org>
Acked-by: Alan Cox <alan@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2009-04-23 14:15:26 -07:00
Alexey Dobriyan
6fd69d3cf1 proc tty: switch usb-serial to ->proc_fops
Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
Cc: Alan Cox <alan@lxorguk.ukuu.org.uk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-04-01 08:59:10 -07:00
Dave Young
e4abe6658a usb-serial: fix usb_serial_register bug when boot with nousb param
With "nousb" cmdline booting, built-in serial drivers (ie. airecable)
will trigger kernel oops.

Indeed, if nousb, usb_serial_init will failed, and the usb serial bus type
will not be registerd, then usb_serial_register call driver_register
which try to register the driver to a not registered bus.

Here add usb_disabled() check in usb_serial_register to fix it.

Signed-off-by: Dave Young <hidave.darkstar@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2009-03-24 16:20:33 -07:00
James Woodcock
331879fd6f USB: serial: refuse to open recently removed USB Serial devices
A USB-serial converter device is plugged into a system, and a process
opens it's device node.  If the device is physically removed whilst the
process still has its device node open, then other processes can
sucessfully open the now non-existent device's node.  I would expect
that open() on a device that has been physically removed should return
ENODEV.

This is manifesting itself with getty on my system.  I do the following:
1.  set up inittab to spawn getty on ttyUSB0, eg:
    T1:23:respawn:/sbin/getty -L ttyUSB0 115200 vt100
2.  Plug in USB-serial converter cable
3.  Wait for a login prompt on a terminal program attached to the serial
    cable
4.  Login
5.  Pull the USB-serial converter cable from the box
6.  getty doesn't realise that ttyUSB0 no longer exists as /dev/ttyUSB0
    can still be opened.
7.  Re-insert the USB-serial converter cable
8.  You should no longer get a login prompt over the serial cable, as
    the the USB-serial cable now shows up as /dev/ttyUSB1, and getty is
    trying to talk to /dev/ttyUSB0.

The attached patch will cause open("/dev/ttyUSB0", O_RDONLY) to return
ENODEV after the USB-serial converter has been pulled.  The patch was
created against 2.6.28.1.  I can supply it against something else if
needs be.  It is fairly simple, so should be OK.

I am using a pl2303 device, although I don't think that makes any
difference.


From: James Woodcock <James.Woodcock@ACULAB.COM>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2009-03-24 16:20:31 -07:00
Oliver Neukum
1c27ae671e USB: serial: remove recourse to generic method
This removes the fallback to the generic method. It is cleaner to
explicitely request it. Introducing this was my mistake. This will
be solved by an explicit test and the driver being allowed to request
what it needs to be done upon resumption.

Signed-off-by: Oliver Neukum <oneukum@suse.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2009-03-24 16:20:30 -07:00
Oliver Neukum
c49cfa9170 USB: serial: use generic method if no alternative is provided in usb serial layer
This patch makes use of the generic method if a serial driver provides
no implementation. This simplifies implementing suspend/resume support
in serial drivers.

Signed-off-by: Oliver Neukum <oneukum@suse.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2009-03-24 16:20:30 -07:00