The meaning of CONFIG_EMBEDDED has long since been obsoleted; the option
is used to configure any non-standard kernel with a much larger scope than
only small devices.

This patch renames the option to CONFIG_EXPERT in init/Kconfig and fixes
references to the option throughout the kernel.  A new CONFIG_EMBEDDED
option is added that automatically selects CONFIG_EXPERT when enabled and
can be used in the future to isolate options that should only be
considered for embedded systems (RISC architectures, SLOB, etc).

Calling the option "EXPERT" more accurately represents its intention: only
expert users who understand the impact of the configuration changes they
are making should enable it.
Reviewed-by: NIngo Molnar <mingo@elte.hu>
Acked-by: NDavid Woodhouse <david.woodhouse@intel.com>
Signed-off-by: NDavid Rientjes <rientjes@google.com>
Cc: Greg KH <gregkh@suse.de>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Robin Holt <holt@sgi.com>
Cc: <linux-arch@vger.kernel.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

The following code is defined but never used.
Signed-off-by: NStephen Hemminger <shemminger@vyatta.com>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

All file_operations should get a .llseek operation so we can make
nonseekable_open the default for future file operations without a
.llseek pointer.

The three cases that we can automatically detect are no_llseek, seq_lseek
and default_llseek. For cases where we can we can automatically prove that
the file offset is always ignored, we use noop_llseek, which maintains
the current behavior of not returning an error from a seek.

New drivers should normally not use noop_llseek but instead use no_llseek
and call nonseekable_open at open time.  Existing drivers can be converted
to do the same when the maintainer knows for certain that no user code
relies on calling seek on the device file.

The generated code is often incorrectly indented and right now contains
comments that clarify for each added line why a specific variant was
chosen. In the version that gets submitted upstream, the comments will
be gone and I will manually fix the indentation, because there does not
seem to be a way to do that using coccinelle.

Some amount of new code is currently sitting in linux-next that should get
the same modifications, which I will do at the end of the merge window.

Many thanks to Julia Lawall for helping me learn to write a semantic
patch that does all this.

===== begin semantic patch =====
// This adds an llseek= method to all file operations,
// as a preparation for making no_llseek the default.
//
// The rules are
// - use no_llseek explicitly if we do nonseekable_open
// - use seq_lseek for sequential files
// - use default_llseek if we know we access f_pos
// - use noop_llseek if we know we don't access f_pos,
//   but we still want to allow users to call lseek
//
@ open1 exists @
identifier nested_open;
@@
nested_open(...)
{
<+...
nonseekable_open(...)
...+>
}

@ open exists@
identifier open_f;
identifier i, f;
identifier open1.nested_open;
@@
int open_f(struct inode *i, struct file *f)
{
<+...
(
nonseekable_open(...)
|
nested_open(...)
)
...+>
}

@ read disable optional_qualifier exists @
identifier read_f;
identifier f, p, s, off;
type ssize_t, size_t, loff_t;
expression E;
identifier func;
@@
ssize_t read_f(struct file *f, char *p, size_t s, loff_t *off)
{
<+...
(
   *off = E
|
   *off += E
|
   func(..., off, ...)
|
   E = *off
)
...+>
}

@ read_no_fpos disable optional_qualifier exists @
identifier read_f;
identifier f, p, s, off;
type ssize_t, size_t, loff_t;
@@
ssize_t read_f(struct file *f, char *p, size_t s, loff_t *off)
{
... when != off
}

@ write @
identifier write_f;
identifier f, p, s, off;
type ssize_t, size_t, loff_t;
expression E;
identifier func;
@@
ssize_t write_f(struct file *f, const char *p, size_t s, loff_t *off)
{
<+...
(
  *off = E
|
  *off += E
|
  func(..., off, ...)
|
  E = *off
)
...+>
}

@ write_no_fpos @
identifier write_f;
identifier f, p, s, off;
type ssize_t, size_t, loff_t;
@@
ssize_t write_f(struct file *f, const char *p, size_t s, loff_t *off)
{
... when != off
}

@ fops0 @
identifier fops;
@@
struct file_operations fops = {
 ...
};

@ has_llseek depends on fops0 @
identifier fops0.fops;
identifier llseek_f;
@@
struct file_operations fops = {
...
 .llseek = llseek_f,
...
};

@ has_read depends on fops0 @
identifier fops0.fops;
identifier read_f;
@@
struct file_operations fops = {
...
 .read = read_f,
...
};

@ has_write depends on fops0 @
identifier fops0.fops;
identifier write_f;
@@
struct file_operations fops = {
...
 .write = write_f,
...
};

@ has_open depends on fops0 @
identifier fops0.fops;
identifier open_f;
@@
struct file_operations fops = {
...
 .open = open_f,
...
};

// use no_llseek if we call nonseekable_open
////////////////////////////////////////////
@ nonseekable1 depends on !has_llseek && has_open @
identifier fops0.fops;
identifier nso ~= "nonseekable_open";
@@
struct file_operations fops = {
...  .open = nso, ...
+.llseek = no_llseek, /* nonseekable */
};

@ nonseekable2 depends on !has_llseek @
identifier fops0.fops;
identifier open.open_f;
@@
struct file_operations fops = {
...  .open = open_f, ...
+.llseek = no_llseek, /* open uses nonseekable */
};

// use seq_lseek for sequential files
/////////////////////////////////////
@ seq depends on !has_llseek @
identifier fops0.fops;
identifier sr ~= "seq_read";
@@
struct file_operations fops = {
...  .read = sr, ...
+.llseek = seq_lseek, /* we have seq_read */
};

// use default_llseek if there is a readdir
///////////////////////////////////////////
@ fops1 depends on !has_llseek && !nonseekable1 && !nonseekable2 && !seq @
identifier fops0.fops;
identifier readdir_e;
@@
// any other fop is used that changes pos
struct file_operations fops = {
... .readdir = readdir_e, ...
+.llseek = default_llseek, /* readdir is present */
};

// use default_llseek if at least one of read/write touches f_pos
/////////////////////////////////////////////////////////////////
@ fops2 depends on !fops1 && !has_llseek && !nonseekable1 && !nonseekable2 && !seq @
identifier fops0.fops;
identifier read.read_f;
@@
// read fops use offset
struct file_operations fops = {
... .read = read_f, ...
+.llseek = default_llseek, /* read accesses f_pos */
};

@ fops3 depends on !fops1 && !fops2 && !has_llseek && !nonseekable1 && !nonseekable2 && !seq @
identifier fops0.fops;
identifier write.write_f;
@@
// write fops use offset
struct file_operations fops = {
... .write = write_f, ...
+	.llseek = default_llseek, /* write accesses f_pos */
};

// Use noop_llseek if neither read nor write accesses f_pos
///////////////////////////////////////////////////////////

@ fops4 depends on !fops1 && !fops2 && !fops3 && !has_llseek && !nonseekable1 && !nonseekable2 && !seq @
identifier fops0.fops;
identifier read_no_fpos.read_f;
identifier write_no_fpos.write_f;
@@
// write fops use offset
struct file_operations fops = {
...
 .write = write_f,
 .read = read_f,
...
+.llseek = noop_llseek, /* read and write both use no f_pos */
};

@ depends on has_write && !has_read && !fops1 && !fops2 && !has_llseek && !nonseekable1 && !nonseekable2 && !seq @
identifier fops0.fops;
identifier write_no_fpos.write_f;
@@
struct file_operations fops = {
... .write = write_f, ...
+.llseek = noop_llseek, /* write uses no f_pos */
};

@ depends on has_read && !has_write && !fops1 && !fops2 && !has_llseek && !nonseekable1 && !nonseekable2 && !seq @
identifier fops0.fops;
identifier read_no_fpos.read_f;
@@
struct file_operations fops = {
... .read = read_f, ...
+.llseek = noop_llseek, /* read uses no f_pos */
};

@ depends on !has_read && !has_write && !fops1 && !fops2 && !has_llseek && !nonseekable1 && !nonseekable2 && !seq @
identifier fops0.fops;
@@
struct file_operations fops = {
...
+.llseek = noop_llseek, /* no read or write fn */
};
===== End semantic patch =====
Signed-off-by: NArnd Bergmann <arnd@arndb.de>
Cc: Julia Lawall <julia@diku.dk>
Cc: Christoph Hellwig <hch@infradead.org>

Change "return (EXPR);" to "return EXPR;"

return is not a function, parentheses are not required.
Signed-off-by: NEric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

include cleanup: Update gfp.h and slab.h includes to prepare for breaking implicit slab.h inclusion from percpu.h

percpu.h is included by sched.h and module.h and thus ends up being
included when building most .c files.  percpu.h includes slab.h which
in turn includes gfp.h making everything defined by the two files
universally available and complicating inclusion dependencies.

percpu.h -> slab.h dependency is about to be removed.  Prepare for
this change by updating users of gfp and slab facilities include those
headers directly instead of assuming availability.  As this conversion
needs to touch large number of source files, the following script is
used as the basis of conversion.

  http://userweb.kernel.org/~tj/misc/slabh-sweep.py

The script does the followings.

* Scan files for gfp and slab usages and update includes such that
  only the necessary includes are there.  ie. if only gfp is used,
  gfp.h, if slab is used, slab.h.

* When the script inserts a new include, it looks at the include
  blocks and try to put the new include such that its order conforms
  to its surrounding.  It's put in the include block which contains
  core kernel includes, in the same order that the rest are ordered -
  alphabetical, Christmas tree, rev-Xmas-tree or at the end if there
  doesn't seem to be any matching order.

* If the script can't find a place to put a new include (mostly
  because the file doesn't have fitting include block), it prints out
  an error message indicating which .h file needs to be added to the
  file.

The conversion was done in the following steps.

1. The initial automatic conversion of all .c files updated slightly
   over 4000 files, deleting around 700 includes and adding ~480 gfp.h
   and ~3000 slab.h inclusions.  The script emitted errors for ~400
   files.

2. Each error was manually checked.  Some didn't need the inclusion,
   some needed manual addition while adding it to implementation .h or
   embedding .c file was more appropriate for others.  This step added
   inclusions to around 150 files.

3. The script was run again and the output was compared to the edits
   from #2 to make sure no file was left behind.

4. Several build tests were done and a couple of problems were fixed.
   e.g. lib/decompress_*.c used malloc/free() wrappers around slab
   APIs requiring slab.h to be added manually.

5. The script was run on all .h files but without automatically
   editing them as sprinkling gfp.h and slab.h inclusions around .h
   files could easily lead to inclusion dependency hell.  Most gfp.h
   inclusion directives were ignored as stuff from gfp.h was usually
   wildly available and often used in preprocessor macros.  Each
   slab.h inclusion directive was examined and added manually as
   necessary.

6. percpu.h was updated not to include slab.h.

7. Build test were done on the following configurations and failures
   were fixed.  CONFIG_GCOV_KERNEL was turned off for all tests (as my
   distributed build env didn't work with gcov compiles) and a few
   more options had to be turned off depending on archs to make things
   build (like ipr on powerpc/64 which failed due to missing writeq).

   * x86 and x86_64 UP and SMP allmodconfig and a custom test config.
   * powerpc and powerpc64 SMP allmodconfig
   * sparc and sparc64 SMP allmodconfig
   * ia64 SMP allmodconfig
   * s390 SMP allmodconfig
   * alpha SMP allmodconfig
   * um on x86_64 SMP allmodconfig

8. percpu.h modifications were reverted so that it could be applied as
   a separate patch and serve as bisection point.

Given the fact that I had only a couple of failures from tests on step
6, I'm fairly confident about the coverage of this conversion patch.
If there is a breakage, it's likely to be something in one of the arch
headers which should be easily discoverable easily on most builds of
the specific arch.
Signed-off-by: NTejun Heo <tj@kernel.org>
Guess-its-ok-by: NChristoph Lameter <cl@linux-foundation.org>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Lee Schermerhorn <Lee.Schermerhorn@hp.com>

This patch renames the (never officially released) sysfs-knobs
"blocked_hw" and "blocked_sw" to "hard" and "soft", as the hardware vs
software conotation is misleading.

It also gets rid of not needed locks around u32-read-access.
Signed-off-by: NFlorian Mickler <florian@mickler.org>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

This commit introduces two new sysfs knobs.

/sys/class/rfkill/rfkill[0-9]+/blocked_hw: (ro)
	hardblock kill state
/sys/class/rfkill/rfkill[0-9]+/blocked_sw: (rw)
	softblock kill state
Signed-off-by: NFlorian Mickler <florian@mickler.org>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

Add support for handling KEY_RFKILL in the rfkill input module. This
simply toggles the state of all rfkill devices. The comment in rfkill.h
is also updated to reflect that RFKILL_TYPE_ALL may be used inside the
kernel.
Signed-off-by: NMatthew Garrett <mjg@redhat.com>
Acked-by: NMarcel Holtmann <marcel@holtmann.org>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

net/rfkill/core.c: In function 'rfkill_type_show':
net/rfkill/core.c:610: warning: control may reach end of non-void function 'rfkill_get_type_str' being inlined

A gcc bug, but simple enough to squish.

Cc: John W. Linville <linville@tuxdriver.com>
Cc: Johannes Berg <johannes@sipsolutions.net>
Cc: David S. Miller <davem@davemloft.net>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

The /dev/rfkill ops don't refer to the module,
so it is possible to unload the module while
file descriptors are open. Fix this oversight.
Reported-by: NMaxim Levitsky <maximlevitsky@gmail.com>
Cc: stable@kernel.org
Signed-off-by: NJohannes Berg <johannes@sipsolutions.net>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

Signed-off-by: NMarcel Holtmann <marcel@holtmann.org>
Signed-off-by: NJanakiram Sistla <janakiram.sistla@gmail.com>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

Signed-off-by: NAlexey Dobriyan <adobriyan@gmail.com>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Althoug GPS is a technology w/o transmitting radio
and thus not a primary candidate for rfkill switch,
rfkill gives unified interface point for devices with
wireless technology.

The input key is not supplied as it is too be deprecated.

Cc: johannes@sipsolutions.net
Signed-off-by: NTomas Winkler <tomas.winkler@intel.com>
Acked-by: NMarcel Holtmann <marcel@holtmann.org>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

The point of this function is to set the software and hardware state at
the same time.  When I tried to use it, I found it was only setting the
software state.
Signed-off-by: NAlan Jenkins <alan-jenkins@tuffmail.co.uk>
Reviewed-by: NJohannes Berg <johannes@sipsolutions.net>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

Apparently there actually _are_ tools that try to set
this in sysfs even though it wasn't supposed to be used
this way without claiming first. Guess what: now that
I've cleaned it all up it doesn't matter and we can
simply allow setting the soft-block state in sysfs.
Signed-off-by: NJohannes Berg <johannes@sipsolutions.net>
Tested-By: NDarren Salt <linux@youmustbejoking.demon.co.uk>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

We've designed the /dev/rfkill API in a way that we
can increase the event struct by adding members at
the end, should it become necessary. To validate the
events, userspace and the kernel need to have the
proper event size to check for -- when reading from
the other end they need to verify that it's at least
version 1 of the event API, with the current struct
size, so define a constant for that and make the
code a little more 'future proof'.

Not that I expect that we'll have to change the event
size any time soon, but it's better to write the code
in a way that lends itself to extending.

Due to the current size of the event struct, the code
is currently equivalent, but should the event struct
ever need to be increased the new code might not need
changing.
Signed-off-by: NJohannes Berg <johannes@sipsolutions.net>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

This information allows userspace to implement a hybrid policy where
it can store the rfkill soft-blocked state in platform non-volatile
storage if available, and if not then file-based storage can be used.

Some users prefer platform non-volatile storage because of the behaviour
when dual-booting multiple versions of Linux, or if the rfkill setting
is changed in the BIOS setting screens, or if the BIOS responds to
wireless-toggle hotkeys itself before the relevant platform driver has
been loaded.
Signed-off-by: NAlan Jenkins <alan-jenkins@tuffmail.co.uk>
Acked-by: NHenrique de Moraes Holschuh <hmh@hmh.eng.br>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

The setting of the "persistent" flag is also made more explicit using
a new rfkill_init_sw_state() function, instead of special-casing
rfkill_set_sw_state() when it is called before registration.

Suspend is a bit of a corner case so we try to get away without adding
another hack to rfkill-input - it's going to be removed soon.
If the state does change over suspend, users will simply have to prod
rfkill-input twice in order to toggle the state.

Userspace policy agents will be able to implement a more consistent user
experience.  For example, they can avoid the above problem if they
toggle devices individually.  Then there would be no "global state"
to get out of sync.

Currently there are only two rfkill drivers with persistent soft-blocked
state.  thinkpad-acpi already checks the software state on resume.
eeepc-laptop will require modification.
Signed-off-by: NAlan Jenkins <alan-jenkins@tuffmail.co.uk>
CC: Marcel Holtmann <marcel@holtmann.org>
Acked-by: NHenrique de Moraes Holschuh <hmh@hmh.eng.br>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

If we return after fiddling with the state, userspace will see the
wrong state and rfkill_set_sw_state() won't work until the next call to
rfkill_set_block().  At the moment rfkill_set_block() will always be
called from rfkill_resume(), but this will change in future.

Also, presumably the point of this test is to avoid bothering devices
which may be suspended.  If we don't want to call set_block(), we
probably don't want to call query() either :-).
Signed-off-by: NAlan Jenkins <alan-jenkins@tuffmail.co.uk>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

Once rfkill-input is disabled, the "global" states will only be used as
default initial states.

Since the states will always be the same after resume, we shouldn't
generate events on resume.
Signed-off-by: NAlan Jenkins <alan-jenkins@tuffmail.co.uk>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

rfkill_set_global_sw_state() (previously rfkill_set_default()) will no
longer be exported by the rewritten rfkill core.

Instead, platform drivers which can provide persistent soft-rfkill state
across power-down/reboot should indicate their initial state by calling
rfkill_set_sw_state() before registration.  Otherwise, they will be
initialized to a default value during registration by a set_block call.

We remove existing calls to rfkill_set_sw_state() which happen before
registration, since these had no effect in the old model.  If these
drivers do have persistent state, the calls can be put back (subject
to testing :-).  This affects hp-wmi and acer-wmi.

Drivers with persistent state will affect the global state only if
rfkill-input is enabled.  This is required, otherwise booting with
wireless soft-blocked and pressing the wireless-toggle key once would
have no apparent effect.  This special case will be removed in future
along with rfkill-input, in favour of a more flexible userspace daemon
(see Documentation/feature-removal-schedule.txt).

Now rfkill_global_states[n].def is only used to preserve global states
over EPO, it is renamed to ".sav".
Signed-off-by: NAlan Jenkins <alan-jenkins@tuffmail.co.uk>
Acked-by: NHenrique de Moraes Holschuh <hmh@hmh.eng.br>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

Now that we added the ioctl, there's no need to ask
the user to configure this. We will keep it enabled
for now, and eventually swap the default to n. Also
let embedded users select it only if they need it.
Signed-off-by: NJohannes Berg <johannes@sipsolutions.net>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

It is useful for debugging when we know if something disabled
the in-kernel rfkill input handler.
Signed-off-by: NJohannes Berg <johannes@sipsolutions.net>
Acked-by: NMarcel Holtmann <marcel@holtmann.org>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

The rfkill core didn't initialise the poll delayed work
because it assumed that polling was always done by specifying
the poll function. cfg80211, however, would like to start
polling only later, which is a valid use case and easy to
support, so change rfkill to always initialise the poll
delayed work and thus allow starting polling by calling the
rfkill_resume_polling() function after registration.
Signed-off-by: NJohannes Berg <johannes@sipsolutions.net>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

Sometimes it is necessary to know how the state is,
and it is easier to query rfkill than keep track of
it somewhere else, so add a function for that. This
could later be expanded to return hard/soft block,
but so far that isn't necessary.
Signed-off-by: NJohannes Berg <johannes@sipsolutions.net>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

The new code added by this patch will make rfkill create
a misc character device /dev/rfkill that userspace can use
to control rfkill soft blocks and get status of devices as
well as events when the status changes.

Using it is very simple -- when you open it you can read
a number of times to get the initial state, and every
further read blocks (you can poll) on getting the next
event from the kernel. The same structure you read is
also used when writing to it to change the soft block of
a given device, all devices of a given type, or all
devices.

This also makes CONFIG_RFKILL_INPUT selectable again in
order to be able to test without it present since its
functionality can now be replaced by userspace entirely
and distros and users may not want the input part of
rfkill interfering with their userspace code. We will
also write a userspace daemon to handle all that and
consequently add the input code to the feature removal
schedule.

In order to have rfkilld support both kernels with and
without CONFIG_RFKILL_INPUT (or new kernels after its
eventual removal) we also add an ioctl (that only exists
if rfkill-input is present) to disable rfkill-input.
It is not very efficient, but at least gives the correct
behaviour in all cases.
Signed-off-by: NJohannes Berg <johannes@sipsolutions.net>
Acked-by: NMarcel Holtmann <marcel@holtmann.org>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

This patch completely rewrites the rfkill core to address
the following deficiencies:

 * all rfkill drivers need to implement polling where necessary
   rather than having one central implementation

 * updating the rfkill state cannot be done from arbitrary
   contexts, forcing drivers to use schedule_work and requiring
   lots of code

 * rfkill drivers need to keep track of soft/hard blocked
   internally -- the core should do this

 * the rfkill API has many unexpected quirks, for example being
   asymmetric wrt. alloc/free and register/unregister

 * rfkill can call back into a driver from within a function the
   driver called -- this is prone to deadlocks and generally
   should be avoided

 * rfkill-input pointlessly is a separate module

 * drivers need to #ifdef rfkill functions (unless they want to
   depend on or select RFKILL) -- rfkill should provide inlines
   that do nothing if it isn't compiled in

 * the rfkill structure is not opaque -- drivers need to initialise
   it correctly (lots of sanity checking code required) -- instead
   force drivers to pass the right variables to rfkill_alloc()

 * the documentation is hard to read because it always assumes the
   reader is completely clueless and contains way TOO MANY CAPS

 * the rfkill code needlessly uses a lot of locks and atomic
   operations in locked sections

 * fix LED trigger to actually change the LED when the radio state
   changes -- this wasn't done before
Tested-by: NAlan Jenkins <alan-jenkins@tuffmail.co.uk>
Signed-off-by: Henrique de Moraes Holschuh <hmh@hmh.eng.br> [thinkpad]
Signed-off-by: NJohannes Berg <johannes@sipsolutions.net>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

net/rfkill/rfkill.c: In function 'update_rfkill_state':
net/rfkill/rfkill.c:99: error: implicit declaration of function 'rfkill_led_trigger'

Caused by

: commit 492301fb
: Author: Larry Finger <Larry.Finger@lwfinger.net>
: Date:   Thu Apr 9 22:14:19 2009 -0500
:
:     rfkill: Fix broken rfkill LED in 2.6.30-rc1

Cc: Henrique de Moraes Holschuh <hmh@hmh.eng.br>
Cc: Ivo van Doorn <IvDoorn@gmail.com>
Cc: Michael Buesch <mb@bu3sch.de>
Cc: David S. Miller <davem@davemloft.net>
Cc: Larry Finger <Larry.Finger@lwfinger.net>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

The rfkill system fails to issue a LED trigger event when the rfkill state
changes.
Signed-off-by: NLarry Finger <Larry.Finger@lwfinger.net>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

There's a lot of rfkill-input code that cannot ever be
compiled and is useless until somebody needs and tests
it -- therefore remove it.
Signed-off-by: NJohannes Berg <johannes@sipsolutions.net>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

Almost all drivers do not support user_claim, so remove it
completely and always report -EOPNOTSUPP to userspace. Since
userspace cannot really drive rfkill _anyway_ (due to the
odd restrictions imposed by the documentation) having this
code is just pointless.
Signed-off-by: NJohannes Berg <johannes@sipsolutions.net>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

commit 4dec9b80 ("rfkill: strip pointless
notifier chain") removed the only user of rfkill_led_trigger() that was not
guarded by #ifdef CONFIG_RFKILL_LEDS. Therefore, move rfkill_led_trigger()
completely inside #ifdef CONFIG_RFKILL_LEDS and avoid the compile time
warning:

net/rfkill/rfkill.c:59: warning: 'rfkill_led_trigger' defined but not used
Signed-off-by: NSimon Holm Thøgersen <odie@cs.aau.dk>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

No users, so no reason to have it.
Signed-off-by: NJohannes Berg <johannes@sipsolutions.net>
Acked-by: NIvo van Doorn <IvDoorn@gmail.com>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

We "optimize" away the get_state() hook call on rfkill_toggle_radio
when doing a forced state change.  This means the resume path is not
calling get_state() as it should.

Call it manually on the resume handler, as we don't want to mess with
the EPO path by removing the optimization.  This has the added benefit
of making it explicit that rfkill->state could have been modified
before we hit the rfkill_toggle_radio() call in the class resume
handler.
Signed-off-by: NHenrique de Moraes Holschuh <hmh@hmh.eng.br>
Acked-by: NIvo van Doorn <IvDoorn@gmail.com>
Cc: Matthew Garrett <mjg59@srcf.ucam.org>
Cc: Alan Jenkins <alan-jenkins@tuffmail.co.uk>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

The rfkill class API requires that the driver connected to a class
call rfkill_force_state() on resume to update the real state of the
rfkill controller, OR that it provides a get_state() hook.

This means there is potentially a hidden call in the resume code flow
that changes rfkill->state (i.e. rfkill_force_state()), so the
previous state of the transmitter was being lost.

The simplest and most future-proof way to fix this is to explicitly
store the pre-sleep state on the rfkill structure, and restore from
that on resume.
Signed-off-by: NHenrique de Moraes Holschuh <hmh@hmh.eng.br>
Acked-by: NIvo van Doorn <IvDoorn@gmail.com>
Cc: Matthew Garrett <mjg59@srcf.ucam.org>
Cc: Alan Jenkins <alan-jenkins@tuffmail.co.uk>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

Acked-by: NMarcel Holtmann <marcel@holtmann.org>
Acked-by: NGreg Kroah-Hartman <gregkh@suse.de>
Signed-off-by: NKay Sievers <kay.sievers@vrfy.org>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

> I'll have a prod at why the [hso] rfkill stuff isn't working next

Ok, I believe this is due to the addition of rfkill_check_duplicity in
rfkill and the fact that test_bit actually returns a negative value
rather than the postive one expected (which is of course equally true).
So when the second WLAN device (the hso device, with the EEE PC WLAN
being the first) comes along rfkill_check_duplicity returns a negative
value and so rfkill_register returns an error. Patch below fixes this
for me.
Signed-Off-By: NJonathan McDowell <noodles@earth.li>
Acked-by: NHenrique de Moraes Holschuh <hmh@hmh.eng.br>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

Limit the number of "expensive" rfkill workqueue operations per second, in
order to not hog system resources too much when faced with a rogue source
of rfkill input events.

The old rfkill-input code (before it was refactored) had such a limit in
place.  It used to drop new events that were past the rate limit.  This
behaviour was not implemented as an anti-DoS measure, but rather as an
attempt to work around deficiencies in input device drivers which would
issue multiple KEY_FOO events too soon for a given key FOO (i.e. ones that
do not implement mechanical debouncing properly).

However, we can't really expect such issues to be worked around by every
input handler out there, and also by every userspace client of input
devices.  It is the input device driver's responsability to do debouncing
instead of spamming the input layer with bogus events.

The new limiter code is focused only on anti-DoS behaviour, and tries to
not lose events (instead, it coalesces them when possible).

The transmitters are updated once every 200ms, maximum.  Care is taken not
to delay a request to _enter_ rfkill transmitter Emergency Power Off (EPO)
mode.

If mistriggered (e.g. by a jiffies counter wrap), the code delays processing
*once* by 200ms.
Signed-off-by: NHenrique de Moraes Holschuh <hmh@hmh.eng.br>
Cc: Ivo van Doorn <IvDoorn@gmail.com>
Cc: Dmitry Torokhov <dtor@mail.ru>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

rfkill_resume() would always restore the rfkill controller state to its
pre-suspend state.

Now that we know when we are under EPO, kick the rfkill controller to
SOFT_BLOCKED state instead of to its pre-suspend state when it is resumed
while EPO mode is active.
Signed-off-by: NHenrique de Moraes Holschuh <hmh@hmh.eng.br>
Cc: Ivo van Doorn <IvDoorn@gmail.com>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

Add of software-based sanity to rfkill and rfkill-input so that it can
reproduce what hardware-based EPO switches do, blocking all transmitters
and locking down any further attempts to unblock them until the switch is
deactivated.

rfkill-input is responsible for issuing the EPO control requests, like
before.

While an rfkill EPO is active, all transmitters are locked to one of the
BLOCKED states and all attempts to change that through the rfkill API
(userspace and kernel) will be either ignored or return -EPERM errors.

The lock will be released upon receipt of EV_SW SW_RFKILL_ALL ON by
rfkill-input, or should modular rfkill-input be unloaded.

This makes rfkill and rfkill-input extend the operation of an existing
wireless master kill switch to all wireless devices in the system, even
those that are not under hardware or firmware control.

Since the above is the expected operational behavior for the master rfkill
switch, the EPO lock functionality is not optional.

Also, extend rfkill-input to allow for three different behaviors when it
receives an EV_SW SW_RFKILL_ALL ON input event.  The user can set which
behavior he wants through the master_switch_mode parameter:

master_switch_mode = 0: EV_SW SW_RFKILL_ALL ON just unlocks rfkill
controller state changes (so that the rfkill userspace and kernel APIs can
now be used to change rfkill controller states again), but doesn't change
any of their states (so they will all remain blocked).  This is the safest
mode of operation, as it requires explicit operator action to re-enable a
transmitter.

master_switch_mode = 1: EV_SW SW_RFKILL_ALL ON causes rfkill-input to
attempt to restore the system to the state before the last EV_SW
SW_RFKILL_ALL OFF event, or to the default global states if no EV_SW
SW_RFKILL_ALL OFF ever happened.   This is the recommended mode of
operation for laptops.

master_switch_mode = 2: tries to unblock all rfkill controllers (i.e.
enable all transmitters) when an EV_SW SW_RFKILL_ALL ON event is received.
This is the default mode of operation, as it mimics the previous behavior
of rfkill-input.

In order to implement these features in a clean way, the entire event
handling of rfkill-input was refactored into a single worker function.

Protection against input event DoS (repeatedly firing rfkill events for
rfkill-input to process) was removed during the code refactoring.  It will
be added back in a future patch.

Note that with these changes, rfkill-input doesn't need to explicitly
handle any radio types for which KEY_<radio type> or SW_<radio type> events
do not exist yet.

Code to handle EV_SW SW_{WLAN,WWAN,BLUETOOTH,WIMAX,...} was added as it
might be needed in the future (and its implementation is not that obvious),
but is currently #ifdef'd out to avoid wasting resources.
Signed-off-by: NHenrique de Moraes Holschuh <hmh@hmh.eng.br>
Cc: Ivo van Doorn <IvDoorn@gmail.com>
Cc: Dmitry Torokhov <dtor@mail.ru>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>