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: Alan Cox <alan@redhat.com>
Cc: Paul Fulghum <paulkf@microgate.com>
Signed-off-by: Hirokazu Takata <takata@linux-m32r.org>
Signed-off-by: Serge Hallyn <serue@us.ibm.com>
Signed-off-by: Jeff Dike <jdike@addtoit.com>
Signed-off-by: John Hawkes <hawkes@sgi.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Signed-off-by: Adrian Bunk <bunk@stusta.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
These haven't worked in some time, and we've dropped support for the bus
from the SH tree until someone shows some interest in maintaining it.
Signed-off-by: Paul Mundt <lethal@linux-sh.org>
Signed-off-by: Dmitry Torokhov <dtor@mail.ru>
Avoid doing assignments to a live ->fops so it can be marked as 'const'.
Signed-off-by: Arjan van de Ven <arjan@infradead.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Dmitry Torokhov <dtor@mail.ru>
offset can never be < 0 because it has type size_t. The driver
currently oopses on insmod if BIOS does not support the interface,
instead of refusing to load.
Signed-off-by: Miloslav Trmac <mitr@volny.cz>
Signed-off-by: Dmitry Torokhov <dtor@mail.ru>
Many ARM drivers do not need to include asm/irq.h - remove this
unnecessary include from some ARM drivers.
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Some ARM platforms have the ability to program the interrupt controller to
detect various interrupt edges and/or levels. For some platforms, this is
critical to setup correctly, particularly those which the setting is dependent
on the device.
Currently, ARM drivers do (eg) the following:
err = request_irq(irq, ...);
set_irq_type(irq, IRQT_RISING);
However, if the interrupt has previously been programmed to be level sensitive
(for whatever reason) then this will cause an interrupt storm.
Hence, if we combine set_irq_type() with request_irq(), we can then safely set
the type prior to unmasking the interrupt. The unfortunate problem is that in
order to support this, these flags need to be visible outside of the ARM
architecture - drivers such as smc91x need these flags and they're
cross-architecture.
Finally, the SA_TRIGGER_* flag passed to request_irq() should reflect the
property that the device would like. The IRQ controller code should do its
best to select the most appropriate supported mode.
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Since the ARM AMBA bus is used on MIPS as well as ARM, we need
to make the bus available for other architectures to use. Move
the AMBA include files from include/asm-arm/hardware/ to
include/linux/amba/
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Sanitize some s390 Kconfig options. We have ARCH_S390, ARCH_S390X,
ARCH_S390_31, 64BIT, S390_SUPPORT and COMPAT. Replace these 6 options by
S390, 64BIT and COMPAT.
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Call serio_reconnect() instead of serio_rescan() when detecting that
a new keyboard was plugged in. This should help KVM uses losing custom
keymap settings when switching between boxes.
Signed-off-by: Dmitry Torokhov <dtor@mail.ru>
Here's the patch for modalias support for input classes. It uses
comma-separated numbers, and doesn't describe all the potential keys (no
module currently cares, and that would make the strings huge). The
changes to input.h are to move the definitions needed by file2alias
outside __KERNEL__. I chose not to move those definitions to
mod_devicetable.h, because there are so many that it might break compile
of something else in the kernel.
The rest is fairly straightforward.
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
CC: Kay Sievers <kay.sievers@vrfy.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Leave the overloaded "hotplug" word to susbsystems which are handling
real devices. The driver core does not "plug" anything, it just exports
the state to userspace and generates events.
Signed-off-by: Kay Sievers <kay.sievers@suse.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
It makes zero sense to have hotplug, but not the netlink
events enabled today. Remove this option and merge the
kobject_uevent.h header into the kobject.h header file.
Signed-off-by: Kay Sievers <kay.sievers@suse.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
It seems that clk_use() and clk_unuse() are additional complexity
which isn't required anymore. Remove them from the clock framework
to avoid the additional confusion which they cause, and update all
ARM machine types except for OMAP.
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
This patch fixes a typo introduced by conversion to dynamic input_dev
allocation.
Signed-off-by: Dmitry Torokhov <dtor@mail.ru>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Noticed by Christophe Zimmerman, this explains the slow mouse movement
with 2.6.x kernels.
And checking the 2.4.x drivers/sbus/char/sunmouse.c driver shows we
always used a 5-byte protocol with Sun mice in the past. I have no
idea how the 3-byte thing got into the 2.6.x driver, but it's surely
wrong.
Signed-off-by: David S. Miller <davem@davemloft.net>
Do not use platform_device_register_simple() as it is going away,
implement ->probe() and ->remove() functions so manual binding and
unbinding would work.
Signed-off-by: Dmitry Torokhov <dtor@mail.ru>
Do not use platform_device_register_simple() as it is going away,
implement ->probe() and ->remove() functions so manual binding and
unbinding will work with this driver.
Signed-off-by: Dmitry Torokhov <dtor@mail.ru>
Do not use platform_device_register_simple() as it is going away,
implement ->probe() and ->remove() functions so manual binding and
unbinding will work with this driver.
Signed-off-by: Dmitry Torokhov <dtor@mail.ru>
Do not use platform_device_register_simple() as it is going away,
implement ->probe() and ->remove() functions so manual binding and
unbinding will work with this driver.
Signed-off-by: Dmitry Torokhov <dtor@mail.ru>
Do not use platform_device_register_simple() as it is going away,
implement ->probe() and ->remove() functions so manual binding and
unbinding will work with this driver.
Signed-off-by: Dmitry Torokhov <dtor@mail.ru>
Introduce a Kconfig symbol SPARC that is defined on both the sparc and
sparc64 architectures.
This symbol makes some dependencies more readable.
Signed-off-by: Adrian Bunk <bunk@stusta.de>
Signed-off-by: David S. Miller <davem@davemloft.net>
This DMI data was found in Fujitsu LifeBook B142 (Product S/N
FPC01003B, italian keyboard); re: bugzilla #5335
Signed-off-by: Dmitry Torokhov <dtor@mail.ru>
It looks like quite a few mice out there treat PSMOUSE_RESET_DIS
as a powerdown request and turn off the light rendering the mouse
unusable.
Vojtech recommended to switch from PSMOUSE_RESET_DIS to full reset,
however we don't want to do that everywhere as full reset is pretty
slow. Instead we only use it before probing for "generic" protocols,
such as IntelliMouse and Explorer, to make sure that the mouse will
be woken up if it went to sleep as a result of PSMOUSE_RESET_DIS
issued earlier.
Signed-off-by: Dmitry Torokhov <dtor@mail.ru>
Without this patch Forward and Backward buttons on the touchpad do not
generate any events.
Signed-off-by: Dmitry Torokhov <dtor@mail.ru>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Compat and normal code mirror each other and are hard to maintain.
When EV_SW was added compat_ioctl case was missed. Here is my attempt
at consolidating the code.
Signed-off-by: Dmitry Torokhov <dtor@mail.ru>
