Transform some calls to kmalloc/memset to a single kzalloc (or kcalloc).
Here is a short excerpt of the semantic patch performing
this transformation:
@@
type T2;
expression x;
identifier f,fld;
expression E;
expression E1,E2;
expression e1,e2,e3,y;
statement S;
@@
x =
- kmalloc
+ kzalloc
(E1,E2)
... when != \(x->fld=E;\|y=f(...,x,...);\|f(...,x,...);\|x=E;\|while(...) S\|for(e1;e2;e3) S\)
- memset((T2)x,0,E1);
@@
expression E1,E2,E3;
@@
- kzalloc(E1 * E2,E3)
+ kcalloc(E1,E2,E3)
[akpm@linux-foundation.org: get kcalloc args the right way around]
Signed-off-by: Yoann Padioleau <padator@wanadoo.fr>
Cc: Richard Henderson <rth@twiddle.net>
Cc: Ivan Kokshaysky <ink@jurassic.park.msu.ru>
Acked-by: Russell King <rmk@arm.linux.org.uk>
Cc: Bryan Wu <bryan.wu@analog.com>
Acked-by: Jiri Slaby <jirislaby@gmail.com>
Cc: Dave Airlie <airlied@linux.ie>
Acked-by: Roland Dreier <rolandd@cisco.com>
Cc: Jiri Kosina <jkosina@suse.cz>
Acked-by: Dmitry Torokhov <dtor@mail.ru>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Acked-by: Mauro Carvalho Chehab <mchehab@infradead.org>
Acked-by: Pierre Ossman <drzeus-list@drzeus.cx>
Cc: Jeff Garzik <jeff@garzik.org>
Cc: "David S. Miller" <davem@davemloft.net>
Acked-by: Greg KH <greg@kroah.com>
Cc: James Bottomley <James.Bottomley@steeleye.com>
Cc: "Antonino A. Daplas" <adaplas@pol.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
drivers/input/serio/serio_raw.c: In function 'serio_raw_read':
drivers/input/serio/serio_raw.c:163: warning: 'c' may be used uninitialized in this function
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Dmitry Torokhov <dtor@mail.ru>
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/dtor/input:
Input: document some of keycodes
Input: add a new EV_SW SW_RADIO event, for radio switches on laptops
Input: serio - take drv_mutex in serio_cleanup()
Input: atkbd - use printk_ratelimit for spurious ACK messages
Input: atkbd - throttle LED switching
Input: i8042 - add HP Pavilion ZT1000 to the MUX blacklist
We need to take serio->drv_mutex in serio_cleanup() to prevent the
function from being called while driver is in the middle of attaching
to a serio port. Such situation can happen with i8042 and atkbd drivers
if user rapidly presses Ctrl-Alt-Del during system startup, and leads
to kernel oops.
Reported-by: Dave Young <hidave.darkstar@gmail.com>
Signed-off-by: Dmitry Torokhov <dtor@mail.ru>
This should get rid of "atkbd.c: Suprious NAK on isa0060/serio0"
messages caused by broken MUX implementation. The box does not
have external PS/2 ports and, according to documentation,
automatically disables touchpad when an external mouse is plugged
into a port replicator, so MUX mode would not work anyway.
Signed-off-by: Dmitry Torokhov <dtor@mail.ru>
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/dtor/input:
Input: move input-polldev to drivers/input
Input: i8042 - add ULI EV4873 to noloop list
Input: i8042 - add ASUS P65UP5 to the noloop list
Input: usbtouchscreen - fix fallout caused by move from drivers/usb
The box does not implement AUX LOOP command properly and so we
can't test for AUX IRQ delivery so blacklist it via DMI and
assume that AUX port is present.
Signed-off-by: Dmitry Torokhov <dtor@mail.ru>
This board does not raise AUX IRQ in response to AUX LOOP command
which interferes with our test for proper AUX IRQ wiring. Put it
in the blacklist and assume mouse is present.
Signed-off-by: Dmitry Torokhov <dtor@mail.ru>
The i8042 driver fails detection of the AUX port with some chips,
because they apparently do not change the I8042_CTR_AUXDIS bit
immediately. This is known to affect at least HP500/HP510 notebooks,
consequently the built-in touchpad will not work. The patch will simply
reread the value until it gets the expected value or a retry limit is
hit, without touching other workaround code in the same area.
Signed-off-by: Roland Scheidegger <sroland@tungstengraphics.com>
Signed-off-by: Dmitry Torokhov <dtor@mail.ru>
The subsystem rwsem is not used by the driver core at all, so there is
no point in trying to access it.
Signed-off-by: Dmitry Torokhov <dtor@mail.ru>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
There is no data coming from touchscreen on Panasonic CF-29
notebook unless keyboard controller is in legacy mode.
Signed-off-by: Dmitry Torokhov <dtor@mail.ru>
Disable both keyboard and auxiliary interfaces before switching
to legacy mode to prevent atkbd from getting "empty" interrupts.
Signed-off-by: Dmitry Torokhov <dtor@mail.ru>
This should get rid of "atkbd.c: Suprious NAK on isa0060/serio0"
messages caused by broken MUX implementation. The box does not
have external PS/2 ports so disabling MUX mode is safe.
Signed-off-by: Dmitry Torokhov <dtor@mail.ru>
Do not assume that AUX_LOOP command is broken unless it
completes successfully but returns wrong (unexpected) data.
Signed-off-by: Dmitry Torokhov <dtor@mail.ru>
- mark some structures const or __read_mostly
- hilkbd.c: fix uninitialized spinlock in HIL keyboard driver
- hil_mlc.c: use USEC_PER_SEC instead of 1000000
- hp_sdc: bugfix for request_irq()/free_irq() parameters, this prevented
multiple load/unload cycles as module
Signed-off-by: Helge Deller <deller@gmx.de>
Signed-off-by: Dmitry Torokhov <dtor@mail.ru>
* 'for-linus' of master.kernel.org:/pub/scm/linux/kernel/git/dtor/input:
Input: remove obsolete setup parameters from input drivers
Input: HIL - fix improper call to release_region()
Input: hid-lgff - treat devices as joysticks unless told otherwise
Input: HID - add support for Logitech Formula Force EX
Input: gpio-keys - switch to common GPIO API
Input: do not lock device when showing name, phys and uniq
Input: i8042 - let serio bus suspend ports
Input: psmouse - properly reset mouse on shutdown/suspend
Let serio subsystem take care of suspending the ports; concentrate
on suspending/resuming the controller itself.
Signed-off-by: Dmitry Torokhov <dtor@mail.ru>
The C99 specification states in section 6.11.5:
The placement of a storage-class specifier other than at the
beginning of the declaration specifiers in a declaration is an
obsolescent feature.
Signed-off-by: Tobias Klauser <tklauser@distanz.ch>
Signed-off-by: Adrian Bunk <bunk@stusta.de>
After Al Viro (finally) succeeded in removing the sched.h #include in module.h
recently, it makes sense again to remove other superfluous sched.h includes.
There are quite a lot of files which include it but don't actually need
anything defined in there. Presumably these includes were once needed for
macros that used to live in sched.h, but moved to other header files in the
course of cleaning it up.
To ease the pain, this time I did not fiddle with any header files and only
removed #includes from .c-files, which tend to cause less trouble.
Compile tested against 2.6.20-rc2 and 2.6.20-rc2-mm2 (with offsets) on alpha,
arm, i386, ia64, mips, powerpc, and x86_64 with allnoconfig, defconfig,
allmodconfig, and allyesconfig as well as a few randconfigs on x86_64 and all
configs in arch/arm/configs on arm. I also checked that no new warnings were
introduced by the patch (actually, some warnings are removed that were emitted
by unnecessarily included header files).
Signed-off-by: Tim Schmielau <tim@physik3.uni-rostock.de>
Acked-by: Russell King <rmk+kernel@arm.linux.org.uk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Many struct file_operations in the kernel can be "const". Marking them const
moves these to the .rodata section, which avoids false sharing with potential
dirty data. In addition it'll catch accidental writes at compile time to
these shared resources.
Signed-off-by: Arjan van de Ven <arjan@linux.intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
On boxes that do not implement AUX LOOP command we can not
verify AUX IRQ delivery and must assume that it is wired
properly.
Signed-off-by: Dmitry Torokhov <dtor@mail.ru>
This adds the module name to all SERIO drivers, if they are built into
the kernel or not. It will show up in /sys/modules/MODULE_NAME/drivers/
Cc: Kay Sievers <kay.sievers@suse.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
On some boxes panic blink procedure manages to send both bytes
to keyboard contoller before getting first ACK so we need to
make i8042_suppress_kbd_ack a counter instead of boolean.
Signed-off-by: Dmitry Torokhov <dtor@mail.ru>
We need to pass in the resource otherwise we cannot
release the region properly. We must know whether it is
an I/O or MEM resource.
Spotted by Eric Brower.
Signed-off-by: David S. Miller <davem@davemloft.net>
We already had entry for Fujitsu Lifebook P7010 in the nomux
blacklist but for some reason Fujitsu decided to fiddle with
DMI data...
Signed-off-by: Dmitry Torokhov <dtor@mail.ru>
Move process freezing functions from include/linux/sched.h to freezer.h, so
that modifications to the freezer or the kernel configuration don't require
recompiling just about everything.
[akpm@osdl.org: fix ueagle driver]
Signed-off-by: Nigel Cunningham <nigel@suspend2.net>
Cc: "Rafael J. Wysocki" <rjw@sisk.pl>
Cc: Pavel Machek <pavel@ucw.cz>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Conflicts:
drivers/infiniband/core/iwcm.c
drivers/net/chelsio/cxgb2.c
drivers/net/wireless/bcm43xx/bcm43xx_main.c
drivers/net/wireless/prism54/islpci_eth.c
drivers/usb/core/hub.h
drivers/usb/input/hid-core.c
net/core/netpoll.c
Fix up merge failures with Linus's head and fix new compilation failures.
Signed-Off-By: David Howells <dhowells@redhat.com>
This also ment that some of the misc drivers had to also be fixed
up as they were assuming the device was a class_device.
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Perform actual driver registration right in serio_register_driver()
instead of offloading it to kseriod and return proper error code to
callers if driver registration fails.
Note that driver <-> port matching is still done by kseriod to
speed up boot process since probing for PS/2 mice and keyboards
is pretty slow.
Signed-off-by: Dmitry Torokhov <dtor@mail.ru>
Pass the work_struct pointer to the work function rather than context data.
The work function can use container_of() to work out the data.
For the cases where the container of the work_struct may go away the moment the
pending bit is cleared, it is made possible to defer the release of the
structure by deferring the clearing of the pending bit.
To make this work, an extra flag is introduced into the management side of the
work_struct. This governs auto-release of the structure upon execution.
Ordinarily, the work queue executor would release the work_struct for further
scheduling or deallocation by clearing the pending bit prior to jumping to the
work function. This means that, unless the driver makes some guarantee itself
that the work_struct won't go away, the work function may not access anything
else in the work_struct or its container lest they be deallocated.. This is a
problem if the auxiliary data is taken away (as done by the last patch).
However, if the pending bit is *not* cleared before jumping to the work
function, then the work function *may* access the work_struct and its container
with no problems. But then the work function must itself release the
work_struct by calling work_release().
In most cases, automatic release is fine, so this is the default. Special
initiators exist for the non-auto-release case (ending in _NAR).
Signed-Off-By: David Howells <dhowells@redhat.com>
MUX error handling has a workaround for KBCs that get confused which
port data came from and signal MUXERR while data is actually good.
Unfortunately this workaround hurts with KBCs that signal timeouts
as 0xfc (spec says that only 0xfd, 0xfe and 0xff are alowed with
MUXERR) since it causes endless attempts to rescan i8042 serio
ports. The solution is to treat 0xfc as timeout (0xfe).
Signed-off-by: Dmitry Torokhov <dtor@mail.ru>
Remove call to i8042_interrupt() from i8042_aux_write(). According
to Vojtech it may cause problems with older controllers if it is
called right after real interrupt. Also it is not needed anymore
since we register IRQs early and not waiting for serio ports to
be opened.
Signed-off-by: Dmitry Torokhov <dtor@mail.ru>
Initialize serio_bus structure at compile time instead of at runtime
in serio_init().
Signed-off-by: Marton Nemeth <nm127@freemail.hu>
Signed-off-by: Dmitry Torokhov <dtor@mail.ru>
Enable HIL configuration options on HP300
Signed-off-by: Kars de Jong <jongk@linux-m68k.org>
Signed-off-by: Geert Uytterhoeven <geert@linux-m68k.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Maintain a per-CPU global "struct pt_regs *" variable which can be used instead
of passing regs around manually through all ~1800 interrupt handlers in the
Linux kernel.
The regs pointer is used in few places, but it potentially costs both stack
space and code to pass it around. On the FRV arch, removing the regs parameter
from all the genirq function results in a 20% speed up of the IRQ exit path
(ie: from leaving timer_interrupt() to leaving do_IRQ()).
Where appropriate, an arch may override the generic storage facility and do
something different with the variable. On FRV, for instance, the address is
maintained in GR28 at all times inside the kernel as part of general exception
handling.
Having looked over the code, it appears that the parameter may be handed down
through up to twenty or so layers of functions. Consider a USB character
device attached to a USB hub, attached to a USB controller that posts its
interrupts through a cascaded auxiliary interrupt controller. A character
device driver may want to pass regs to the sysrq handler through the input
layer which adds another few layers of parameter passing.
I've build this code with allyesconfig for x86_64 and i386. I've runtested the
main part of the code on FRV and i386, though I can't test most of the drivers.
I've also done partial conversion for powerpc and MIPS - these at least compile
with minimal configurations.
This will affect all archs. Mostly the changes should be relatively easy.
Take do_IRQ(), store the regs pointer at the beginning, saving the old one:
struct pt_regs *old_regs = set_irq_regs(regs);
And put the old one back at the end:
set_irq_regs(old_regs);
Don't pass regs through to generic_handle_irq() or __do_IRQ().
In timer_interrupt(), this sort of change will be necessary:
- update_process_times(user_mode(regs));
- profile_tick(CPU_PROFILING, regs);
+ update_process_times(user_mode(get_irq_regs()));
+ profile_tick(CPU_PROFILING);
I'd like to move update_process_times()'s use of get_irq_regs() into itself,
except that i386, alone of the archs, uses something other than user_mode().
Some notes on the interrupt handling in the drivers:
(*) input_dev() is now gone entirely. The regs pointer is no longer stored in
the input_dev struct.
(*) finish_unlinks() in drivers/usb/host/ohci-q.c needs checking. It does
something different depending on whether it's been supplied with a regs
pointer or not.
(*) Various IRQ handler function pointers have been moved to type
irq_handler_t.
Signed-Off-By: David Howells <dhowells@redhat.com>
(cherry picked from 1b16e7ac850969f38b375e511e3fa2f474a33867 commit)
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/dtor/input: (35 commits)
Input: wistron - add support for Acer TravelMate 2424NWXCi
Input: wistron - fix setting up special buttons
Input: add KEY_BLUETOOTH and KEY_WLAN definitions
Input: add new BUS_VIRTUAL bus type
Input: add driver for stowaway serial keyboards
Input: make input_register_handler() return error codes
Input: remove cruft that was needed for transition to sysfs
Input: fix input module refcounting
Input: constify input core
Input: libps2 - rearrange exports
Input: atkbd - support Microsoft Natural Elite Pro keyboards
Input: i8042 - disable MUX mode on Toshiba Equium A110
Input: i8042 - get rid of polling timer
Input: send key up events at disconnect
Input: constify psmouse driver
Input: i8042 - add Amoi to the MUX blacklist
Input: logips2pp - add sugnature 56 (Cordless MouseMan Wheel), cleanup
Input: add driver for Touchwin serial touchscreens
Input: add driver for Touchright serial touchscreens
Input: add driver for Penmount serial touchscreens
...
ppc can boot one single binary on prep, chrp and pmac boards. ppc64 can
boot one single binary on pseries and G5 boards. pmac has no legacy io,
probing for PC style legacy hardware (or accessing the legacy io area
regulary) may lead to a hard crash:
* add check for parport_pc, exit on pmac. 32bit chrp has no
->check_legacy_ioport, the probe is always called. 64bit chrp has
check_legacy_ioport, check for a "parallel" node
* add check for isapnp, only PReP boards may have real ISA slots. 32bit
PReP will have no ->check_legacy_ioport, the probe is always called.
* update code in i8042_platform_init. Run ->check_legacy_ioport first,
always call request_region. No functional change. Remove whitespace
before i8042_reset init.
Signed-off-by: Olaf Hering <olaf@aepfle.de>
Acked-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Adam Belay <ambx1@neo.rr.com>
Cc: Dmitry Torokhov <dtor@mail.ru>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Microsoft Natural Elite Pro keyboard produces unisual response to
the GET ID command - single byte 0xaa (normally keyboards produce
2-byte response). Fail GET ID command so atkbd gets a change to
do alternate probe.
Signed-off-by: Dmitry Torokhov <dtor@mail.ru>
When keyboard controller is in active multiplexing mode ALPS touchpad
may get detected twice. Since the box does not have external PS/2
ports simply disabling MUX mode is safe solution.
Signed-off-by: Dmitry Torokhov <dtor@mail.ru>
Remove polling timer that was used to detect keybord/mice hotplug and
register both IRQs right away instead of waiting for a driver to
attach to a port.
Signed-off-by: Dmitry Torokhov <dtor@mail.ru>
ALPS touchpad on Amoi laptops (Amoi is a vendor in China) is not
detected when keyboard controller is in MUX mode, add to blacklist.
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Dmitry Torokhov <dtor@mail.ru>
The PS/2 code has a natural device order and there is a one level recursion in
this device order in terms of the cmd_mutex; annotate this explicit recursion
as ok.
Has no effect on non-lockdep kernels.
Signed-off-by: Arjan van de Ven <arjan@linux.intel.com>
Cc: Dmitry Torokhov <dtor_core@ameritech.net>
Cc: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
drivers/input/serio/i8042-sparcio.h:91: error: '__mod_of_device_table' aliased to undefined symbol 'i8042_match'
Cc: Dmitry Torokhov <dtor_core@ameritech.net>
DESC
sparc: resource warning fix
EDESC
From: Andrew Morton <akpm@osdl.org>
sound/sparc/amd7930.c: In function 'amd7930_attach_common':
sound/sparc/amd7930.c:1040: warning: format '%08lx' expects type 'long unsigned int', but argument 5 has type 'resource_size_t'
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/devfs-2.6: (22 commits)
[PATCH] devfs: Remove it from the feature_removal.txt file
[PATCH] devfs: Last little devfs cleanups throughout the kernel tree.
[PATCH] devfs: Rename TTY_DRIVER_NO_DEVFS to TTY_DRIVER_DYNAMIC_DEV
[PATCH] devfs: Remove the tty_driver devfs_name field as it's no longer needed
[PATCH] devfs: Remove the line_driver devfs_name field as it's no longer needed
[PATCH] devfs: Remove the videodevice devfs_name field as it's no longer needed
[PATCH] devfs: Remove the gendisk devfs_name field as it's no longer needed
[PATCH] devfs: Remove the miscdevice devfs_name field as it's no longer needed
[PATCH] devfs: Remove the devfs_fs_kernel.h file from the tree
[PATCH] devfs: Remove devfs_remove() function from the kernel tree
[PATCH] devfs: Remove devfs_mk_cdev() function from the kernel tree
[PATCH] devfs: Remove devfs_mk_bdev() function from the kernel tree
[PATCH] devfs: Remove devfs_mk_symlink() function from the kernel tree
[PATCH] devfs: Remove devfs_mk_dir() function from the kernel tree
[PATCH] devfs: Remove devfs_*_tape() functions from the kernel tree
[PATCH] devfs: Remove devfs support from the sound subsystem
[PATCH] devfs: Remove devfs support from the ide subsystem.
[PATCH] devfs: Remove devfs support from the serial subsystem
[PATCH] devfs: Remove devfs from the init code
[PATCH] devfs: Remove devfs from the partition code
...
This is needed if we wish to change the size of the resource structures.
Based on an original patch from Vivek Goyal <vgoyal@in.ibm.com>
Cc: Vivek Goyal <vgoyal@in.ibm.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Some people report that we die on some Macs when we are expecting to
catch machine checks after poking at some random I/O address. I'd seen
it happen on my dual G4 with serial ports until we fixed those to use
OF, but now other users are reporting it with i8042.
This expands the use of check_legacy_ioport() to avoid that situation
even on 32-bit kernels.
Signed-off-by: David Woodhouse <dwmw2@infradead.org>
Signed-off-by: Paul Mackerras <paulus@samba.org>
Addresses in F-space must be accessed uncached on most parisc machines.
Signed-off-by: Helge Deller <deller@parisc-linux.org>
Signed-off-by: Kyle McMartin <kyle@parisc-linux.org>
this changes if() BUG(); constructs to BUG_ON() which is
cleaner and can better optimized away
Signed-off-by: Eric Sesterhenn <snakebyte@gmx.de>
Signed-off-by: Adrian Bunk <bunk@stusta.de>
this changes if() BUG(); constructs to BUG_ON() which is
cleaner and can better optimized away
Signed-off-by: Eric Sesterhenn <snakebyte@gmx.de>
Signed-off-by: Adrian Bunk <bunk@stusta.de>
Do not assume that pnp_register_driver() returns the number of
devices claimed.
Signed-off-by: Bjorn Helgaas <bjorn.helgaas@hp.com>
Signed-off-by: Dmitry Torokhov <dtor@mail.ru>
Serio and gameport cores do not depend on other drivers and are
used by code living outside of drivers/input/{gameport|serio}.
Registering them at subsystem level guarantees that they are
fully initialized before anyone tries to use them.
Signed-off-by: Dmitry Torokhov <dtor@mail.ru>
The conversion was generated via scripts, and the result was validated
automatically via a script as well.
Signed-off-by: Arjan van de Ven <arjan@infradead.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Dmitry Torokhov <dtor@mail.ru>
98kbd{,-io} and 98spkr all went out with PC98 subarch. Remove stale Makefile
entries that remained.
Signed-off-by: Arthur Othieno <apgo@patchbomb.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Dmitry Torokhov <dtor@mail.ru>
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>
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>
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>
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 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>
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>
