Add a dummy LL interface to the Gigaset driver so that it can be
built and, in a limited way, used without the ISDN4Linux subsystem.

Impact: new configuration alternative
Signed-off-by: NTilman Schmidt <tilman@imap.cc>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Reorganize the code of the Gigaset driver, moving all isdn4linux
dependencies to the source file i4l.c so that it can be replaced
by a file capi.c interfacing to Kernel CAPI instead.

Impact: refactoring, no functional change
Signed-off-by: NTilman Schmidt <tilman@imap.cc>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Add kerneldoc comments to some functions in the Gigaset driver.

Impact: documentation
Signed-off-by: NTilman Schmidt <tilman@imap.cc>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Dump payload data consistently only when DEBUG_STREAM_DUMP debug bit
is set.

Impact: debugging aid
Signed-off-by: NTilman Schmidt <tilman@imap.cc>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

When the Gigaset base stops responding, try resetting the USB
connection to recover.

Impact: error handling improvement
Signed-off-by: NTilman Schmidt <tilman@imap.cc>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Clear out pending command that got rejected with 'ERROR' response.
This fixes the bug where unloading the driver module would hang
with the message: "gigaset: not searching scheduled commands: busy"
after a device communication error.

Impact: error handling bugfix
Signed-off-by: NTilman Schmidt <tilman@imap.cc>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Mention in the driver load announcement whether the driver was built
with debugging messages enabled, to facilitate support.

Impact: informational message
Signed-off-by: NTilman Schmidt <tilman@imap.cc>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Don't drop the remainder of an URB if an isochronous frame has an error.

Impact: error handling improvement
Signed-off-by: NTilman Schmidt <tilman@imap.cc>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

The code of the Gigaset driver assumes that sk_buff-s coming
from the ISDN4Linux subsystem are always linear. Explicitly
calling skb_linearize() is cheap if they are, but much more
robust in case they ever aren't.

Impact: robustness improvement
Signed-off-by: NTilman Schmidt <tilman@imap.cc>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Signal D channel disconnect in a few cases where it was missed,
including when an incoming call is disconnected before it was
accepted.

Impact: error handling improvement
Signed-off-by: NTilman Schmidt <tilman@imap.cc>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

The tty_operation chars_in_buffer() is not allowed to return a negative
value to signal an error.  Corrects the problem flagged by commit
23198fda, "tty: fix chars_in_buffers".
Signed-off-by: NTilman Schmidt <tilman@imap.cc>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: stable <stable@kernel.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>

This function does not have an error return and returning an error is
instead interpreted as having a lot of pending bytes.

Reported by Jeff Harris who provided a list of some of the remaining
offenders.
Signed-off-by: NAlan Cox <alan@linux.intel.com>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Drop a sanity check which doesn't serve any useful purpose anymore.
Signed-off-by: NTilman Schmidt <tilman@imap.cc>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

ISDN connection setup failed if the "connection active" and
"B channel up" messages from the device arrived in a different
order than expected. Modify the state machine to accept them in
any order.

Impact: bugfix
Signed-off-by: NTilman Schmidt <tilman@imap.cc>
CC: stable <stable@kernel.org>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Signed-off-by: NRoel Kluin <roel.kluin@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

The B channel data structure member rcvbytes was never set to
anything else but zero, so drop it.

Impact: cleanup
Signed-off-by: NTilman Schmidt <tilman@imap.cc>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Drop the kernel config option GIGASET_UNDOCREQ, permanently
activating the code it controlled, as there have been no reports
of problems caused by its activation but many problems caused by
it being disabled.
Also fix a few bad comments while we're at it.

Impact: cleanup
Signed-off-by: NTilman Schmidt <tilman@imap.cc>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

In preparation for porting to kernel CAPI subsystem, include the
Gigaset driver's Kconfig directly from ISDN's instead of I4L's.

Impact: Kconfig reorganisation, no functional change
Signed-off-by: NTilman Schmidt <tilman@imap.cc>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

gigaset_register_to_LL() is expected to print a message and return 0
on failure. Make it do so consistently.

Impact: error handling bugfix
Signed-off-by: NTilman Schmidt <tilman@imap.cc>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Don't generate the hex representation of the payload data if it
isn't actually used afterwards.

Impact: optimization
Signed-off-by: NTilman Schmidt <tilman@imap.cc>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Use pr_warning() / pr_err() instead of dev_warn() / dev_err() in two
places where the dev pointer isn't guaranteed to be valid.

Impact: error handling bugfix
Signed-off-by: NTilman Schmidt <tilman@imap.cc>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

The separation of state tables for base and M10x has long been
removed. Clean up remaining traces of it.

Impact: cleanup
Signed-off-by: NTilman Schmidt <tilman@imap.cc>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

When the device is disconnected, the dev structure goes away, so
trying to report another error via dev_printk is bound to oops.
To avoid that, first check whether the device is still connected
and return quietly if it isn't.

Impact: error handling
Signed-off-by: NTilman Schmidt <tilman@imap.cc>
Reported-by: NPaul Bolle <pebolle@tiscali.nl>
Tested-by: NPaul Bolle <pebolle@tiscali.nl>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

The tasklets for isochronous data transfer need to run within 8 msec
to avoid over/underruns, so schedule them with high priority to fix
reported issues with occasional over/underruns.
Signed-off-by: NTilman Schmidt <tilman@imap.cc>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

This helps the code look more consistent and cleaner.
Signed-off-by: NEric Miao <eric.miao@marvell.com>
Cc: Kay Sievers <kay.sievers@vrfy.org>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>

Every USB transfer buffer has to be allocated individually by kmalloc.

Impact: bugfix, no functional change
Signed-off-by: NTilman Schmidt <tilman@imap.cc>
Tested-by: NKolja Waschk <kawk@users.sourceforge.net>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

A number of functions in the usb_gigaset module will return -EINVAL if
CONFIG_GIGASET_UNDOCREQ is not set. Make these return -ENOTTY as it's
more specific and it might make it easier to see (from userspace) why
these functions actually fail.

Impact: some error return codes changed
Signed-off-by: NPaul Bolle <pebolle@tiscali.nl>
Signed-off-by: NTilman Schmidt <tilman@imap.cc>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Streamline dependencies and remove some obsolete or redundant comments
in the Gigaset ISDN driver's Kconfig file. In particular, remove the
strong warning against the GIGASET_UNDOCREQ option, as in seven years
of existence, the code in question has never been reported to cause
any harm.

Impact: Kconfig cleanup, no functional change
Signed-off-by: NTilman Schmidt <tilman@imap.cc>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Remove unnecessary #ifdef-s and #if-0-ed code sections.
Signed-off-by: NTilman Schmidt <tilman@imap.cc>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Switch from private printk wrapper macros to using pr_err() and
pr_info() from linux/kernel.h, at the same time unifying a few
error messages.
Signed-off-by: NTilman Schmidt <tilman@imap.cc>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Join the move away from the obsolete info() macro, opencoding the
remaining uses. While we're at it, also get rid of the warn() macro
by promoting the three remaining uses to err().
Signed-off-by: NTilman Schmidt <tilman@imap.cc>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

The N_GIGASET_M101 line discipline implemented by the ser_gigaset
driver does not transfer any data from/to userspace through the
tty interface. Therefore a poll method is not needed.
Signed-off-by: NTilman Schmidt <tilman@imap.cc>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Stephen's fixes reminded me that gigaset is still rather broken so fix it up
a bit
Signed-off-by: NAlan Cox <alan@redhat.com>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Today's linux-next build (x86_64 allmodconfig) failed like this:

/drivers/char/tty_ioctl.c: In function 'change_termios':
drivers/isdn/capi/capi.c:1234: error: implicit declaration of function 'n_tty_ioctl'
drivers/isdn/gigaset/ser-gigaset.c: In function 'gigaset_tty_ioctl':
drivers/isdn/gigaset/ser-gigaset.c:648: error: implicit declaration of function 'n_tty_ioctl'

Introduced by commit 686b5e4aea05a80e370dc931b7f4a8d03c80da54
("tty-move-canon-specials").  I added the following patch (which may not
be correct).
Signed-off-by: NStephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: NAlan Cox <alan@redhat.com>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Signed-off-by: NHarvey Harrison <harvey.harrison@gmail.com>
Acked-by: NKarsten Keil <kkeil@suse.de>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

ifd->offset is unsigned.  gigaset_isowbuf_getbytes() may return signed
unnoticed.  Revised version of patch originally submitted by Roel Kluin
<12o3l@tiscali.nl>.
Signed-off-by: NTilman Schmidt <tilman@imap.cc>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

The info() / warn() / err() macros from usb.h for generating kernel
messages are considered inferior to dev_info() / dev_warn() / dev_err()
from device.h.  Replace them where possible.  Also correct the severity
level and improve the text of one message.
Signed-off-by: NTilman Schmidt <tilman@imap.cc>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Move the line disciplines towards a conventional ->ops arrangement.  For
the moment the actual 'tty_ldisc' struct in the tty is kept as part of
the tty struct but this can then be changed if it turns out that when it
all settles down we want to refcount ldiscs separately to the tty.

Pull the ldisc code out of /proc and put it with our ldisc code.
Signed-off-by: NAlan Cox <alan@redhat.com>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

- Operations are now a shared const function block as with most other Linux
  objects

- Introduce wrappers for some optional functions to get consistent behaviour

- Wrap put_char which used to be patched by the tty layer

- Document which functions are needed/optional

- Make put_char report success/fail

- Cache the driver->ops pointer in the tty as tty->ops

- Remove various surplus lock calls we no longer need

- Remove proc_write method as noted by Alexey Dobriyan

- Introduce some missing sanity checks where certain driver/ldisc
  combinations would oops as they didn't check needed methods were present

[akpm@linux-foundation.org: fix fs/compat_ioctl.c build]
[akpm@linux-foundation.org: fix isicom]
[akpm@linux-foundation.org: fix arch/ia64/hp/sim/simserial.c build]
[akpm@linux-foundation.org: fix kgdb]
Signed-off-by: NAlan Cox <alan@redhat.com>
Acked-by: NGreg Kroah-Hartman <gregkh@suse.de>
Cc: Jason Wessel <jason.wessel@windriver.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

The card state mutex was only initialized when a device was connected,
but used during unload unconditionally, leading to an Oops if a driver
was loaded and unloaded again without ever connecting a device.

Fix this by initializing the mutex as soon as the structure is allocated.
Also add a missing mutex unlock revealed in the same execution path.

This fixes a possible Oops in 2.6.25-rc that was introduced by commit
e468c048 ("Gigaset: permit module
unload").

Thanks to Roland Kletzing for reporting this problem.
Signed-off-by: NTilman Schmidt <tilman@imap.cc>
Tested-by: NRoland Kletzing <devzero@web.de>
Cc: Hansjoerg Lipp <hjlipp@web.de>
Cc: Karsten Keil <kkeil@suse.de>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>