The API and code have been through various bits of initial review by
serial driver people but they definitely need to live somewhere for a
while so the unconverted drivers can get knocked into shape, existing
drivers that have been updated can be better tuned and bugs whacked out.

This replaces the tty flip buffers with kmalloc objects in rings. In the
normal situation for an IRQ driven serial port at typical speeds the
behaviour is pretty much the same, two buffers end up allocated and the
kernel cycles between them as before.

When there are delays or at high speed we now behave far better as the
buffer pool can grow a bit rather than lose characters. This also means
that we can operate at higher speeds reliably.

For drivers that receive characters in blocks (DMA based, USB and
especially virtualisation) the layer allows a lot of driver specific
code that works around the tty layer with private secondary queues to be
removed. The IBM folks need this sort of layer, the smart serial port
people do, the virtualisers do (because a virtualised tty typically
operates at infinite speed rather than emulating 9600 baud).

Finally many drivers had invalid and unsafe attempts to avoid buffer
overflows by directly invoking tty methods extracted out of the innards
of work queue structs. These are no longer needed and all go away. That
fixes various random hangs with serial ports on overflow.

The other change in here is to optimise the receive_room path that is
used by some callers. It turns out that only one ldisc uses receive room
except asa constant and it updates it far far less than the value is
read. We thus make it a variable not a function call.

I expect the code to contain bugs due to the size alone but I'll be
watching and squashing them and feeding out new patches as it goes.

Because the buffers now dynamically expand you should only run out of
buffering when the kernel runs out of memory for real.  That means a lot of
the horrible hacks high performance drivers used to do just aren't needed any
more.

Description:

tty_insert_flip_char is an old API and continues to work as before, as does
tty_flip_buffer_push() [this is why many drivers dont need modification].  It
does now also return the number of chars inserted

There are also

tty_buffer_request_room(tty, len)

which asks for a buffer block of the length requested and returns the space
found.  This improves efficiency with hardware that knows how much to
transfer.

and tty_insert_flip_string_flags(tty, str, flags, len)

to insert a string of characters and flags

For a smart interface the usual code is

    len = tty_request_buffer_room(tty, amount_hardware_says);
    tty_insert_flip_string(tty, buffer_from_card, len);

More description!

At the moment tty buffers are attached directly to the tty.  This is causing a
lot of the problems related to tty layer locking, also problems at high speed
and also with bursty data (such as occurs in virtualised environments)

I'm working on ripping out the flip buffers and replacing them with a pool of
dynamically allocated buffers.  This allows both for old style "byte I/O"
devices and also helps virtualisation and smart devices where large blocks of
data suddenely materialise and need storing.

So far so good.  Lots of drivers reference tty->flip.*.  Several of them also
call directly and unsafely into function pointers it provides.  This will all
break.  Most drivers can use tty_insert_flip_char which can be kept as an API
but others need more.

At the moment I've added the following interfaces, if people think more will
be needed now is a good time to say

 int tty_buffer_request_room(tty, size)

Try and ensure at least size bytes are available, returns actual room (may be
zero).  At the moment it just uses the flipbuf space but that will change.
Repeated calls without characters being added are not cumulative.  (ie if you
call it with 1, 1, 1, and then 4 you'll have four characters of space.  The
other functions will also try and grow buffers in future but this will be a
more efficient way when you know block sizes.

 int tty_insert_flip_char(tty, ch, flag)

As before insert a character if there is room.  Now returns 1 for success, 0
for failure.

 int tty_insert_flip_string(tty, str, len)

Insert a block of non error characters.  Returns the number inserted.

 int tty_prepare_flip_string(tty, strptr, len)

Adjust the buffer to allow len characters to be added.  Returns a buffer
pointer in strptr and the length available.  This allows for hardware that
needs to use functions like insl or mencpy_fromio.
Signed-off-by: NAlan Cox <alan@redhat.com>
Cc: Paul Fulghum <paulkf@microgate.com>
Signed-off-by: NHirokazu Takata <takata@linux-m32r.org>
Signed-off-by: NSerge Hallyn <serue@us.ibm.com>
Signed-off-by: NJeff Dike <jdike@addtoit.com>
Signed-off-by: NJohn Hawkes <hawkes@sgi.com>
Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>
Signed-off-by: NAdrian Bunk <bunk@stusta.de>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

Looks like JSM will be uncompilable after the TTY layer rework is merged into
Linus's post-2.6.15 tree.

It was complex to fix - the maintainers were notified in September.

Cc: Wendy Xiong <wendyx@us.ltcfwd.linux.ibm.com>
Cc: Alan Cox <alan@lxorguk.ukuu.org.uk>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

This patch contains the possible cleanups including the following:
- every file should #include the headers containing the prototypes for
  it's global functions
- make needlessly global functions static
- kyro/STG4000Interface.h: #include video/kyro.h and linux/pci.h
  instead of a manual "struct pci_dev"
- i810_main.{c,h}: prototypes for static functions belong to the
  C file
Signed-off-by: NAdrian Bunk <bunk@stusta.de>
Acked-by: N"Antonino A. Daplas" <adaplas@hotpop.com>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

No need to define RTC_NUM_RESOURCES, it doesn't add any value to the code.
Signed-off-by: NJean Delvare <khali@linux-fr.org>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

Use ARRAY_SIZE macro instead of sizeof(x)/sizeof(x[0]) and remove
duplicates of ARRAY_SIZE.
Signed-off-by: NTobias Klauser <tklauser@nuerscht.ch>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

ICC likes to complain about storage class not being first, GCC doesn't
care much (except for cases like "inline static").
have a hard time seeing how it could break anything.

Thanks to Gabriel A. Devenyi for pointing out
http://linuxicc.sourceforge.net/ which is what made me create this patch.
Signed-off-by: NJesper Juhl <jesper.juhl@gmail.com>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

This patch contains the following cleanups:
- make a needlessly global function static
- remove the unneeded global function irport_probe
Signed-off-by: NAdrian Bunk <bunk@stusta.de>
Cc: Jeff Garzik <jgarzik@pobox.com>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

Fix typos in comments to remove kernel-doc warnings.
Signed-off-by: NMartin Waitz <tali@admingilde.org>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

Current console blanking code is broken.  It will first do a normal blank,
then start the VESA blank timer if vesa_off_interval != 0, and then proceed
to do the VESA blanking directly.  After the timer expires it will do the
VESA blanking a second time.  Also the vesa_powerdown() function doesn't
allow all VESA modes to be used.

With this patch the behaviour is:
1. Blank: vesa_off_interval != 0 -> Do normal blank
          vesa_off_interval == 0 -> Do VESA blank
2. Start the VESA blank timer if vesa_off_interval != 0 and
   vesa_power_mode != 0.

It also gets rid of the limiting vesa_powerdown() function.
Signed-off-by: NVille Syrjala <syrjala@sci.fi>
Cc: "Antonino A. Daplas" <adaplas@pol.net>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

While the code in fbmem.c allows for hooking read/write access to
non-linear frame buffers by means of fb_read and fb_write in struct fb_ops,
I could not find a way tho access the actual frame buffer memory from
within these routines.  I therefore had to patch fbmem.c, to be able to
retrieve a pointer to struct fb_info from the 'file' argument to these
functions.

The second hunk of the patch is not strictly required, I only did that for
symmetry reasons (and the code is somewhat shorter).
Signed-off-by: NThomas Koeller <thomas@koeller.dyndns.org>
Acked-by: N"Antonino A. Daplas" <adaplas@gmail.com>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

Signed-off-by: NYOSHIFUJI Hideaki <yoshfuji@linux-ipv6.org>
Cc: "Antonino A. Daplas" <adaplas@pol.net>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

Replace kmalloc with kzalloc
Signed-off-by: NAntonino Daplas <adaplas@pol.net>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

- replace kmalloc with kzalloc
- remove repeated define (FONTCHHCNT)
- remove unneeded local variable (redraw) in ypan_{up|down}_redraw
- add and delete cursor timer in fbcon_switch() if old_info != info
Signed-off-by: NAntonino Daplas <adaplas@pol.net>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

The i810fb suspend and resume hooks have suffered bitrot over time.  Update to
current framework, but functionality still not guaranteed to work.
Signed-off-by: NAntonino Daplas <adaplas@pol.net>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

Here are some cleanups for the s3c2410fb drivers. It :
* Removes a buggy call to s3c2410fb_init_registers. There was two calls
  to this function but the first was done without all initialisations
  done. No oops but it may confuse some LCDs.
* Makes two functions static.
Signed-Off-By: NArnaud Patard <arnaud.patard@rtp-net.org>
Signed-Off-By: NAntonino Daplas <adaplas@pol.net>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

Reduce stack usage of NVCommonSetup()
Signed-off-by: NAntonino Daplas <adaplas@pol.net>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

Add boot/module option 'bpp' so user can specify at what color depth to boot
into.
Signed-off-by: NAntonino Daplas <adaplas@pol.net>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

calc_mode_timings() and fb_get_mode() are using more than 500 bytes off the
stack.  Fix.
Signed-off-by: NAntonino Daplas <adaplas@pol.net>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

Make fb_read() and fb_write() return 0 (EOF) instead of -ENOSPC if reading at
or past the end of the framebuffer.  This fixes user space apps hanging if
info->fix.smem_len == 0.

Whitespace changes.
Signed-off-by: NAntonino Daplas <adaplas@pol.net>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

updatescrollmode() must not select ywrap scrolling if
divides(vc->vc_font.height, yres) is not true as this is not supported by
the actual ywrap scrolling code.

The bug is triggered with e.g.  mode 800x600, vxres 1024, vyres 8192, bpp
8, font dimensions 8x16, 8Mb video ram and FBINFO_HWACCEL_YWRAP set.  If
those conditions are met, scrolling is broken and garbage is permanently
displayed at the bottom of the screen.

No regression, no possible side effects.

Definitely needed by cyblafb and probably needed by amifb.
Signed-off-by: NKnut Petersen <Knut_Petersen@t-online.de>
Acked-by: NAntonino Daplas <adaplas@pol.net>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

Update skeletonfb so it reflects recent (and somewhat old) changes of the
framebuffer layer.
Signed-off-by: NAntonino Daplas <adaplas@pol.net>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

Chipsets with PCI device ids & 0xf0 == 0x00f0 has their actual chipset type in
offset 0x1800 of the mmio space.  Add support for this.
Signed-off-by: NAntonino Daplas <adaplas@pol.net>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

Clean up LT and LG chip descriptions.

"Mach64 LG" is called 3D Rage LT in the specs and ATI press releases.

"Mach64 LT" is unclear.  XFree86 driver doesn't know this chip at all.
Windows display.inf calls it just "mach64 LT" and it uses the same driver as
VT-A/GT-A and older chips.  VT-B/GT-B and better use another driver and all of
those chips have a more descriptive name in the display.inf file.  That makes
me think this chip is not a 3D Rage chip.
Signed-off-by: NVille Syrjälä <syrjala@sci.fi>
Signed-off-by: NAntonino Daplas <adaplas@pol.net>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

Clean up VT and GT chip descriptions.

All B revision VT chips are called 264VT3. Verified from pictures of the
chips as the specs are a bit unlear in this.

GT revision B1 is Rage II, B2 is Rage II+. Specs and chip pictures seem
to agree.

VT revision A4 is 264VT2. Revision A3 is probably a plain 264VT.
Signed-off-by: NVille Syrjälä <syrjala@sci.fi>
Signed-off-by: NAntonino Daplas <adaplas@pol.net>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

Clean up Rage XL/XC chip descriptions.
Signed-off-by: NVille Syrjälä <syrjala@sci.fi>
Signed-off-by: NAntonino Daplas <adaplas@pol.net>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

Force blanking signal and disable display requests when blanked.  Don't
disable LCD backlight with FB_BLANK_NORMAL.
Signed-off-by: NVille Syrjälä <syrjala@sci.fi>
Signed-off-by: NAntonino Daplas <adaplas@pol.net>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

Set ECP (scaler/overlay clock) divider. The limits were taken from the
XFree86 ati driver.
Signed-off-by: NVille Syrjälä <syrjala@sci.fi>
Signed-off-by: NAntonino Daplas <adaplas@pol.net>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

The overlay on 3D Rage LT Pro doesn't work correctly if stretching is
enabled when using only a CRT.
Signed-off-by: NVille Syrjälä <syrjala@sci.fi>
Signed-off-by: NAntonino Daplas <adaplas@pol.net>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

Fix interlaced display modes.
Signed-off-by: NVille Syrjälä <syrjala@sci.fi>
Signed-off-by: NAntonino Daplas <adaplas@pol.net>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

CRTC_FIFO_LWM was incorrectly masked.
Signed-off-by: NVille Syrjälä <syrjala@sci.fi>
Signed-off-by: NAntonino Daplas <adaplas@pol.net>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

Don't complain about invalid modes when FB_ACTIVATE_TEST is used.
Signed-off-by: NVille Syrjälä <syrjala@sci.fi>
Signed-off-by: NAntonino Daplas <adaplas@pol.net>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

Fix some spelling mistakes.
Signed-off-by: NVille Syrjälä <syrjala@sci.fi>
Signed-off-by: NAntonino Daplas <adaplas@pol.net>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

Remove error checking and updating from vga16fb_pan_display.  This is
guaranteed to be done by the core layer.
Signed-off-by: NAntonino Daplas <adaplas@pol.net>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

Fix vesafb hang when scroll mode is REDRAW.
Signed-off-by: NAntonino Daplas <adaplas@pol.net>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

Remove error checking from vesafb_pan_display.  This is guaranteed to be done
by the core layer.
Signed-off-by: NAntonino Daplas <adaplas@pol.net>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

Remove error checking and updating from savagefb_pan_display.  This is
guaranteed to be done by the core layer.
Signed-off-by: NAntonino Daplas <adaplas@pol.net>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

Remove error checking and updating from rivafb_pan_display.  This is
guaranteed to be done by the core layer.
Signed-off-by: NAntonino Daplas <adaplas@pol.net>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

- remove unneeded casts
- make setcolreg return success if regno > 15, but don't do anything
- use framebuffer_alloc/framebuffer_release to allocate/free memory
Signed-off-by: NAntonino Daplas <adaplas@pol.net>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

CONFIG_ATYFB_XL_INIT option is broken for a long time.  It will always cause a
kernel hang.

Since no one has fixed this problem for some time now, remove it from atyfb.
Signed-off-by: NAntonino Daplas <adaplas@pol.net>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

- remove unneeded casts
Signed-off-by: NAntonino Daplas <adaplas@pol.net>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>