For some reason, isdnloop didn't support the transparent encoding,
which is necessary for testing V.110. Testing also found a typo
causing an oops in isdn_common.c. Fixed.

It'd probably make more sense to provide it in library form
to the hardware drivers which don't support V.110 natively, but for
now it's at least collected in one place.

Remove the legacy functions
  
    isdn_slot_readbchan(int slot, u_char *, u_char *, int);
    isdn_slot_driver(int slot);
    isdn_slot_channel(int slot);
    isdn_slot_set_usage(int slot, int usage);
    isdn_drv_writebuf_skb(int di, int ch, int x, struct sk_buff *skb);
    isdn_drv_hdrlen(int di);
  
Most of their tasks have been taken over by isdn_common.c, or are
obsoleted by using the isdn_slot based approach.

Moving the tty receive queue into the tty-specific data in fact
simplifies the common code (which doesn't need to know it at all, now),
and the tty code, which can access the queue more directly.

We used to intercept status callbacks which were for specific channels
instead of the driver before passing them to the driver and short-cutting
to them to the per-channel state machine. Do it correctly for now,
i.e. callback -> driver -> channel, even though that might have a small
performance hit. Correctness first.

ISDN still has a huge global struct called "dev", which is a mess
of parts which should be private to their respective subsystem.
It's supposed to die, this is another step in making that happen.

Change the incoming call logic: Incoming calls are signalled to
the net interface code first, then the tty code. It's the lower level's
responsibility to claim the call by issueing ISDN_CMD_ACCEPTD now.
  
Remove some crud which is handled by isdn_common state machines now.

They were never used except for passing the state to userspace,
but not used in any application I know of. If necessary, the information
can easily be recovered by looking at fi.state == ST_ACTIVE

It wasn't used in any actual hardware driver, nor did it cause any
action at all.

It was never used anywhere (except for debugging output).
  
Also, fix some compiler warnings.

Since we unfortunately cannot rely on the hardware drivers to get
their states always correct, have the common layer keep track of the
states and sanitize them before passing them on to applications
as network interfaces / ttyIs.

We know the driver ids via drivers[]->interface->id already, no need
to keep them around a second time.

It's useless information, we need to iterate over all potential
drivers anyway, since possibly the first one has unregistered before
the second, leaving a hole.

... and move up the function register_isdn().

Currently, we need to provide a couple of helper functions to avoid
breaking isdn_tty with this change, as that gets cleaned up, the need
for those helpers should vanish as well.

read() should be safe against missed wake-ups now. These devices
should actually be implemented by the hardware drivers directly, would
make for much cleaner code. Unfortunately, isdnctrl is
using /dev/isdnctrl for the common ioctls, which are handled by the link
layer, so that's not easily possible. Too bad.

This was broken by removing the CVS revision strings.

The arrays were only allocated and initialized, never used.

Interface type specific stuff is now gone from isdn_net_lib and
taken care of in the individual interface type modules.

This is just simple renaming. However, ISDN/X.25 looks currently
rather badly broken, don't expect it to compile ;(

There's really no need to allocate private storage for all possible
interface types, just leave it to the interface type to alloc the memory
it needs.
  
CISCO HDLC does that, now.

isdn_net_dev and isdn_net_local logically are used by isdn_net_lib,
so let's move them there.

They'll still get compiled all into one module, but now you can choose
what you need - it's not hard to go from here to individual modules,
but most protocol-specific code is so small that it's probably not worth
it.

Though I've been mostly moving stuff out of include/linux and into
drivers/isdn/i4l, the finite state machine definitions actually need
to be more wildly accessible, so they go the opposite way.

Just add the protocol number header to the frame and have MPPP deal with
the entire frame, separating these layers more cleanly.

The revision numbers didn't get updated in ages, so they don't really
make sense anymore.

Updating copyright lines, deleting the CVS $Id lines, move
PPP CCP reset related declarations into drivers/isdn/i4l/isdn_ppp_ccp.c.

Dropping every 7th packet was just meant for internal debugging...

Whoever did the tqueue -> workqueue changes didn't really care to look
at how it was used in the HiSax driver, making the driver compile but
oops with NULL pointer derefs.

Oh, and workqueues are really not the right solution here, tasklets are.
But that's for later.

The reset routines are not called concurrently with other call paths,
and holding a spinlock over schedule_timeout() is plain wrong anyway.

Unfortunately, there's still quite a lot of cli() etc left, which however
are not so easy to kill since they protect IRQ handlers against filling
the tx queue, but don't even live in the same file.

Patches by Frank Davis.

into tp1.ruhr-uni-bochum.de:/home/kai/src/kernel/v2.5/linux-2.5.isdn

From Dipankar

I missed sparc64 when I broke up read_barrier_depends in -mm and sent
to Linus.  Please apply this to your tree until Linus is back and I can
fix it.

Patch from Dipankar Sarma <dipankar@in.ibm.com>

There is a check in RCU for idle CPUs which signifies quiescent state
(and hence no reference to RCU protected data) which was broken when
interrupt counters were changed to use thread_info->preempt_count.

Martin's 32 CPU machine with many idle CPUs was not completing any RCU
grace period because RCU was forever waiting for idle CPUs to context
switch.  Had the idle check worked, this would not have happened.  With
no RCU happening, the dentries were getting "freed" (dentry stats
showing that) but not getting returned to slab.  This would not show up
in systems that are generally busy as context switches then would
happen in all CPUs and the per-CPU quiescent state counter would get
incremented during context switch.

This patch fixes a filesystem corrupting bug, present in 2.5.41 through
2.5.44.  It can cause ext2 indirect blocks to not be written out.  A
fsck will fix it up.

Under heavy memory pressure a PF_MEMALLOC task attemtps to write out a
blockdev page whose buffers are already under writeback and which were
dirtied while under writeback.

The writepage call returns -EAGAIN but because the caller is
PF_MEMALLOC, the page was not being marked dirty again.

The page sits on mapping->clean_pages for ever and it not written out.

The fix is to mark that page dirty again for all callers, regardless of
PF_MEMALLOC state.