Workqueue, 'set_brightness_work' is used for scheduling brightness control.
This workqueue is canceled when the LED class device is unregistered.
Currently, LED subsystem handles like below.
cancel_work_sync(&led_cdev->set_brightness_work)
led_set_brightness(led_cdev, LED_OFF)
However, this could be a problem.
Workqueue is going to be canceled but LED device needs to be off.
The worst case is null pointer access due to scheduling a workqueue.
LED module is loaded.
LED driver private data is allocated by using devm_zalloc().
LED module is unloaded.
led_classdev_unregister() is called.
cancel_work_sync()
led_set_brightness(led_cdev, LED_OFF)
schedule_work() if LED driver uses brightness_set_blocking()
In the meantime, driver private data will be freed.
..scheduling..
brightness_set_blocking() callback is invoked.
For the brightness control, LED driver tries to access private
data but resource is removed!
To avoid this problem, LED subsystem should turn off the brightness first
and wait for completion.
led_set_brightness(led_cdev, LED_OFF)
flush_work(&led_cdev->set_brightness_work)
It guarantees that LED driver turns off the brightness prior to
resource management.
Cc: linux-leds@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Milo Kim <milo.kim@ti.com>
Signed-off-by: Jacek Anaszewski <j.anaszewski@samsung.com>
This patch removes SET_BRIGHTNESS_ASYNC and SET_BRIGHTNESS_SYNC flags.
led_set_brightness() now calls led_set_brightness_nosleep() instead of
choosing between sync and async op basing on the flags defined by the
driver.
From now on, if a user wants to make sure that brightness will be set
synchronously, they have to use led_set_brightness_sync() API. It is now
being made publicly available since it has become apparent that it is
a caller who should decide whether brightness is to be set in
a synchronous or an asynchronous way.
Signed-off-by: Jacek Anaszewski <j.anaszewski@samsung.com>
Acked-by: Sakari Ailus <sakari.ailus@linux.intel.com>
This patch adds led_set_brightness_nosleep() and led_set_brightness_nopm()
functions, that guarantee setting LED brightness in a non-blocking way.
The latter is used from pm_ops context and doesn't modify the brightness
cached in the struct led_classdev. Its execution always ends up with
a call to brightness setting op - either directly or through
a set_brightness_work, regardless of LED_SUSPENDED flag state.
The patch also replaces led_set_brightness_async() with
led_set_brightness_nosleep() in all places where the most vital was setting
brightness in a non sleeping way but not necessarily asynchronously, which
is not needed for non-blocking drivers.
Signed-off-by: Jacek Anaszewski <j.anaszewski@samsung.com>
Acked-by: Sakari Ailus <sakari.ailus@linux.intel.com>
Since the API for controlling LED brightness and blinking is defined in
the LED core, move the related timer and work callbacks to the led-core.c,
and initialize them through a new led_core_init API.
Signed-off-by: Jacek Anaszewski <j.anaszewski@samsung.com>
Acked-by: Andrew Lunn <andrew@lunn.ch>
Acked-by: Pavel Machek <pavel@ucw.cz>
Devices found by class_find_device must be freed with put_device().
Otherwise the reference count will not work properly.
Fixes: a96aa64cb5 ("leds/led-class: Handle LEDs with the same name")
Reported-by: Alan Tull <delicious.quinoa@gmail.com>
Signed-off-by: Ricardo Ribalda Delgado <ricardo.ribalda@gmail.com>
Signed-off-by: Jacek Anaszewski <j.anaszewski@samsung.com>
Pull LED subsystem updates from Bryan Wu:
"In this cycle, we finished to merge patches for LED Flash class
driver.
Other than that we have some bug fixes and new drivers for LED
controllers"
* 'for-next' of git://git.kernel.org/pub/scm/linux/kernel/git/cooloney/linux-leds: (33 commits)
leds:lp55xx: fix firmware loading error
leds: fix max77693-led build errors
leds: fix aat1290 build errors
leds: aat1290: pass flags parameter to devm_gpiod_get
leds: ktd2692: pass flags parameter to devm_gpiod_get
drivers/leds: don't use module_init in non-modular leds-cobalt-raq.c
leds: aat1290: add support for V4L2 Flash sub-device
DT: aat1290: Document handling external strobe sources
leds: max77693: add support for V4L2 Flash sub-device
media: Add registration helpers for V4L2 flash sub-devices
v4l: async: Add a pointer to of_node to struct v4l2_subdev, match it
Documentation: leds: Add description of v4l2-flash sub-device
leds: add BCM6358 LED driver
leds: add DT binding for BCM6358 LED controller
leds: fix brightness changing when software blinking is active
Documentation: leds-lp5523: describe master fader attributes
leds: lp5523: add master_fader support
leds: leds-gpio: Allow compile test if !GPIOLIB
leds: leds-gpio: Add missing #include <linux/of.h>
gpiolib: Add missing dummies for the unified device properties interface
...
The following sequence:
echo timer >/sys/class/leds/<name>/trigger
echo 1 >/sys/class/leds/<name>/brightness
should change the ON brightness for blinking.
The function led_set_brightness() was mistakenly initiating the
delayed blink stop procedure, which resulted in no blinking with
the timer trigger still active.
This patch fixes the problem by changing led_set_brightness()
to not initiate the delayed blink stop when brightness is not 0.
CC: Richard Purdie <rpurdie@rpsys.net>
CC: Kyungmin Park <kyungmin.park@samsung.com>
CC: linux-leds@vger.kernel.org
CC: linux-kernel@vger.kernel.org
Acked-by: Jacek Anaszewski <j.anaszewski@samsung.com>
Signed-off-by: Stas Sergeev <stsp@users.sourceforge.net>
Signed-off-by: Bryan Wu <cooloney@gmail.com>
Setting a dev_pm_ops suspend/resume pair of callbacks but not a set of
hibernation callbacks means those pm functions will not be
called upon hibernation - that leads to system crash on ARM during
freezing if gpio-led is used in combination with CPU led trigger.
It may happen after freeze_noirq stage (GPIO is suspended)
and before syscore_suspend stage (CPU led trigger is suspended)
- usually when disable_nonboot_cpus() is called.
Log:
PM: noirq freeze of devices complete after 1.425 msecs
Disabling non-boot CPUs ...
^ system may crash or stuck here with message (TI AM572x)
WARNING: CPU: 0 PID: 3100 at drivers/bus/omap_l3_noc.c:148 l3_interrupt_handler+0x22c/0x370()
44000000.ocp:L3 Custom Error: MASTER MPU TARGET L4_PER1_P3 (Idle): Data Access in Supervisor mode during Functional access
CPU1: shutdown
^ or here
Fix this by using SIMPLE_DEV_PM_OPS, which appropriately
assigns the suspend and hibernation callbacks and move
led_suspend/led_resume under CONFIG_PM_SLEEP to avoid
build warnings.
Fixes: 73e1ab41a8 (leds: Convert led class driver from legacy pm ops to dev_pm_ops)
Signed-off-by: Grygorii Strashko <Grygorii.Strashko@linaro.org>
Acked-by: Jacek Anaszewski <j.anaszewski@samsung.com>
Cc: 3.11+ <stable@vger.kernel.org> # 3.11+
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
The LED name was wrongly interpreted as format string. Stop doing that.
Signed-off-by: Sakari Ailus <sakari.ailus@linux.intel.com>
Signed-off-by: Bryan Wu <cooloney@gmail.com>
Signed-off-by: Ricardo Ribalda Delgado <ricardo.ribalda@gmail.com>
The LED names are expected to be unique in the system. Use KERN_WARNING log
level to notify the user about the matter.
Signed-off-by: Sakari Ailus <sakari.ailus@linux.intel.com>
Signed-off-by: Bryan Wu <cooloney@gmail.com>
Signed-off-by: Ricardo Ribalda Delgado <ricardo.ribalda@gmail.com>
The current code expected that every LED had an unique name. This is a
legit expectation when the device tree can no be modified or extended.
But with device tree overlays this requirement can be easily broken.
This patch finds out if the name is already in use and adds the suffix
_1, _2... if not.
Signed-off-by: Ricardo Ribalda Delgado <ricardo.ribalda@gmail.com>
Reported-by: Geert Uytterhoeven <geert@linux-m68k.org>
Signed-off-by: Bryan Wu <cooloney@gmail.com>
(cooloney@gmail.com: add _unregister function into the document)
Suggested-by: Stephen Boyd <sboyd@codeaurora.org>
Signed-off-by: Bjorn Andersson <bjorn.andersson@sonymobile.com>
Signed-off-by: Bryan Wu <cooloney@gmail.com>
Some LED devices support two operation modes - torch and flash.
This patch provides support for flash LED devices in the LED subsystem
by introducing new sysfs attributes and kernel internal interface.
The attributes being introduced are: flash_brightness, flash_strobe,
flash_timeout, max_flash_timeout, max_flash_brightness, flash_fault,
flash_sync_strobe and available_sync_leds. All the flash related
features are placed in a separate module.
The modifications aim to be compatible with V4L2 framework requirements
related to the flash devices management. The design assumes that V4L2
sub-device can take of the LED class device control and communicate
with it through the kernel internal interface. When V4L2 Flash sub-device
file is opened, the LED class device sysfs interface is made
unavailable.
Signed-off-by: Jacek Anaszewski <j.anaszewski@samsung.com>
Acked-by: Kyungmin Park <kyungmin.park@samsung.com>
Cc: Richard Purdie <rpurdie@rpsys.net>
Acked-by: Pavel Machek <pavel@ucw.cz>
Signed-off-by: Bryan Wu <cooloney@gmail.com>
Convert a call to init_timer and accompanying intializations of
the timer's data and function fields to a call to setup_timer.
A simplified version of the semantic match that fixes this problem is as
follows: (http://coccinelle.lip6.fr/)
// <smpl>
@@
expression t,f,d;
@@
-init_timer(&t);
+setup_timer(&t,f,d);
-t.function = f;
-t.data = d;
// </smpl>
Signed-off-by: Julia Lawall <Julia.Lawall@lip6.fr>
Signed-off-by: Bryan Wu <cooloney@gmail.com>
There are use cases when setting a LED brightness has to
have immediate effect (e.g. setting a torch LED brightness).
This patch extends LED subsystem to support such operations.
The LED subsystem internal API __led_set_brightness is changed
to led_set_brightness_async and new led_set_brightness_sync API
is added.
Signed-off-by: Jacek Anaszewski <j.anaszewski@samsung.com>
Acked-by: Kyungmin Park <kyungmin.park@samsung.com>
Cc: Richard Purdie <rpurdie@rpsys.net>
Signed-off-by: Bryan Wu <cooloney@gmail.com>
Add a mechanism for locking LED subsystem sysfs interface.
This patch prepares ground for addition of LED Flash Class
extension, whose API will be integrated with V4L2 Flash API.
Such a fusion enforces introducing a locking scheme, which
will secure consistent access to the LED Flash Class device.
The mechanism being introduced allows for disabling LED
subsystem sysfs interface by calling led_sysfs_disable function
and enabling it by calling led_sysfs_enable. The functions
alter the LED_SYSFS_DISABLE flag state and must be called
under mutex lock. The state of the lock is checked with use
of led_sysfs_is_disabled function. Such a design allows for
providing immediate feedback to the user space on whether
the LED Flash Class device is available or is under V4L2 Flash
sub-device control.
Signed-off-by: Jacek Anaszewski <j.anaszewski@samsung.com>
Acked-by: Kyungmin Park <kyungmin.park@samsung.com>
Cc: Richard Purdie <rpurdie@rpsys.net>
Signed-off-by: Bryan Wu <cooloney@gmail.com>
led_update_brightness helper function used to be exploited only locally
in the led-class.c module, where its result was being passed to the
brightness_show sysfs callback. With the introduction of v4l2-flash
subdevice the same functionality becomes required for reading current
brightness from a LED device. This patch adds checking of return value
of the brightness_get callback and moves the led_update_brightness()
function to the LED subsystem public API.
Signed-off-by: Jacek Anaszewski <j.anaszewski@samsung.com>
Acked-by: Kyungmin Park <kyungmin.park@samsung.com>
Cc: Richard Purdie <rpurdie@rpsys.net>
Signed-off-by: Bryan Wu <cooloney@gmail.com>
Make definition of the brightness related sysfs attributes
consistent. The modification entails change of the function
name: led_max_brightness_show -> max_brightness_show
Signed-off-by: Jacek Anaszewski <j.anaszewski@samsung.com>
Acked-by: Sakari Ailus <sakari.ailus@linux.intel.com>
Acked-by: Kyungmin Park <kyungmin.park@samsung.com>
Cc: Richard Purdie <rpurdie@rpsys.net>
Signed-off-by: Bryan Wu <cooloney@gmail.com>
Reorder include directives so that they are arranged
in alphabetical order.
Signed-off-by: Jacek Anaszewski <j.anaszewski@samsung.com>
Acked-by: Kyungmin Park <kyungmin.park@samsung.com>
Cc: Richard Purdie <rpurdie@rpsys.net>
Signed-off-by: Bryan Wu <cooloney@gmail.com>
This patch converts the blink timer from led-core to workqueue which is more
suitable for this kind of non-priority operations. Moreover, timer may lead to
errors when a LED setting function use a scheduling function such as pinctrl
which is using mutex.
Signed-off-by: Vincent Donnefort <vdonnefort@gmail.com>
Signed-off-by: Bryan Wu <cooloney@gmail.com>
Allow led-class devices to be created with optional attribute groups.
This is needed in order to allow led drivers to create custom device
attributes in a race-free manner.
Signed-off-by: Johan Hovold <johan@kernel.org>
Signed-off-by: Bryan Wu <cooloney@gmail.com>
The dev_attrs field of struct class is going away soon, dev_groups
should be used instead. This converts the led class code to use the
correct field.
Acked-by: Bryan Wu <cooloney@gmail.com>
Cc: Richard Purdie <rpurdie@rpsys.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Convert drivers/leds/led-class to use dev_pm_ops for power management and
remove Legacy PM ops hooks. With this change, led class registers
suspend/resume callbacks via class->pm (dev_pm_ops) instead of Legacy
class->suspend/resume. When __device_suspend() runs call-backs, it will
find class->pm ops for the led class.
Signed-off-by: Shuah Khan <shuah.kh@samsung.com>
Signed-off-by: Bryan Wu <cooloney@gmail.com>
Delay execution of led_set_brightness() if need to stop soft-blink
timer.
This allows led_set_brightness to be called in hard-irq context even if
soft-blink was activated on that LED.
Signed-off-by: Fabio Baltieri <fabio.baltieri@gmail.com>
Cc: Pawel Moll <pawel.moll@arm.com>
Signed-off-by: Bryan Wu <bryan.wu@canonical.com>
Rename leds external interface led_brightness_set() to led_set_brightness().
This is the second phase of the change to reduce confusion between the
leds internal and external interfaces that set brightness. With this change,
now the external interface is led_set_brightness(). The first phase renamed
the internal interface led_set_brightness() to __led_set_brightness().
There are no changes to the interface implementations.
Signed-off-by: Shuah Khan <shuahkhan@gmail.com>
Signed-off-by: Bryan Wu <bryan.wu@canonical.com>
Rename leds internal interface led_set_brightness() to __led_set_brightness()
to reduce confusion between led_set_brightness() and the external interface
led_brightness_set(). led_brightness_set() cancels the timer and then calls
led_set_brightness().
Signed-off-by: Shuah Khan <shuahkhan@gmail.com>
Signed-off-by: Bryan Wu <bryan.wu@canonical.com>
Add two new functions, led_blink_set_oneshot and
led_trigger_blink_oneshot, to be used by triggers for one-shot blink of
led devices.
This is implemented extending the existing software-blink code, and uses
the same timer and handler function.
The behavior of the code is to do a blink-on, blink-off sequence when
the function is called, ignoring other calls until the sequence is
completed so that the leds keep blinking at constant rate if the
functions are called repeatedly.
This is meant to be used by drivers which needs to trigger on sporadic
event, but doesn't have clear busy/idle trigger points.
After the blink sequence the led remains off. This behavior can be
inverted setting the "invert" argument, which blink the led off, than on
and leave the led on after the sequence.
(bryan.wu@canonical.com: rebase to commit 'leds: don't disable blinking
when writing the same value to delay_on or delay_off')
Signed-off-by: Fabio Baltieri <fabio.baltieri@gmail.com>
Acked-by: Shuah Khan <shuahkhan@gmail.com>
Signed-off-by: Bryan Wu <bryan.wu@canonical.com>
Fixed a coding style issue relating to trailing
white space error found by checkpatch.pl tool in drivers/leds/led-class.c
Signed-off-by: Jeffrin Jose <ahiliation@yahoo.co.in>
Signed-off-by: Bryan Wu <bryan.wu@canonical.com>
led-class.c and ledtrig-timer.c still use simple_strtoul(). Change them
to use kstrtoul() instead of obsolete simple_strtoul().
Also fix the existing int ret declaration to be ssize_t to match the
return type for _store functions in ledtrig-timer.c.
Signed-off-by: Shuah Khan <shuahkhan@gmail.com>
Cc: Joe Perches <joe@perches.com>
Cc: Richard Purdie <rpurdie@rpsys.net>
Cc: Bryan Wu <bryan.wu@canonical.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
After moving some core functions to led-core.c, led-class.c can be built
as module again.
Signed-off-by: Bryan Wu <bryan.wu@canonical.com>
Acked-by: Richard Purdie <richard.purdie@linuxfoundation.org>
Acked-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This resolves the conflict in the arch/arm/mach-s3c64xx/s3c6400.c file,
and it fixes the build error in the arch/x86/kernel/microcode_core.c
file, that the merge did not catch.
The microcode_core.c patch was provided by Stephen Rothwell
<sfr@canb.auug.org.au> who was invaluable in the merge issues involved
with the large sysdev removal process in the driver-core tree.
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
The sysdev.h file should not be needed by any in-kernel code, so remove
the .h file from these random files that seem to still want to include
it.
The sysdev code will be going away soon, so this include needs to be
removed no matter what.
Cc: Jiandong Zheng <jdzheng@broadcom.com>
Cc: Scott Branden <sbranden@broadcom.com>
Cc: Russell King <linux@arm.linux.org.uk>
Cc: Kukjin Kim <kgene.kim@samsung.com>
Cc: David Brown <davidb@codeaurora.org>
Cc: Daniel Walker <dwalker@fifo99.com>
Cc: Bryan Huntsman <bryanh@codeaurora.org>
Cc: Ben Dooks <ben-linux@fluff.org>
Cc: Wan ZongShun <mcuos.com@gmail.com>
Cc: Haavard Skinnemoen <hskinnemoen@gmail.com>
Cc: Hans-Christian Egtvedt <egtvedt@samfundet.no>
Cc: Guan Xuetao <gxt@mprc.pku.edu.cn>
Cc: "Venkatesh Pallipadi
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Grant Likely <grant.likely@secretlab.ca>
Cc: Richard Purdie <rpurdie@rpsys.net>
Cc: Matthew Garrett <mjg@redhat.com>
Signed-off-by: Kay Sievers <kay.sievers@vrfy.org>
Revert commit 6123b0e274.
The problem this patch intends to solve has alreadqy been fixed by
commit 7a5caabd09 ("drivers/leds/ledtrig-timer.c: fix broken sysfs
delay handling").
Signed-off-by: Johan Hovold <jhovold@gmail.com>
Cc: Antonio Ospite <ospite@studenti.unina.it>
Cc: Johannes Berg <johannes@sipsolutions.net>
Cc: Richard Purdie <rpurdie@rpsys.net>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Depending on the implementation of the hardware blinking function in
blink_set(), the led can support hardware blinking for some values of
delay_on and delay_off and fall-back to software blinking for some other
values.
Turning off the blink_timer unconditionally before starting to blink
make sure that a sequence like:
OFF
hardware blinking
software blinking
hardware blinking
does not leave the software blinking timer active.
Signed-off-by: Antonio Ospite <ospite@studenti.unina.it>
Reviewed-by: Johannes Berg <johannes@sipsolutions.net>
Cc: Richard Purdie <rpurdie@rpsys.net>
Cc: <stable@kernel.org>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
By setting initial values blink_delay_on and blink_delay_off in a
led_classdev struct, this change starts the blinking when the led is
initialized.
With this patch, you can initialize blink_delay_on and blink_delay_off in
led_classdev with default_trigger set to "timer", and the led will start
up blinking. The current ledtrig-timer implementation ignores any initial
blink_delay_on/blink_delay_off settings, and requires setting
blink_delay_on/blink_delay_off (typically from userspace) before the led
blinks.
Signed-off-by: Esben Haabendal <eha@doredevelopment.dk>
Cc: Richard Purdie <rpurdie@rpsys.net>
Cc: Randy Dunlap <rdunlap@xenotime.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
When I added led_blink_set I had a typo: the return value of the hw
offload is a regular error code that is zero when succesful, and in that
case software emulation should not be used, rather than the other way
around.
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Cc: Richard Purdie <rpurdie@linux.intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Currently, blinking LEDs can be awkward because it is not guaranteed that
all LEDs implement blinking. The trigger that wants it to blink then
needs to implement its own timer solution.
Rather than require that, add led_blink_set() API that triggers can use.
This function will attempt to use hw blinking, but if that fails
implements a timer for it. To stop blinking again, brightness_set() also
needs to be wrapped into API that will stop the software blink.
As a result of this, the timer trigger becomes a very trivial one, and
hopefully we can finally see triggers using blinking as well because it's
always easy to use.
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Acked-by: Richard Purdie <rpurdie@linux.intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
max_brightness is not writable, thus set permissions to 0444.
Signed-off-by: Axel Lin <axel.lin@gmail.com>
Signed-off-by: Richard Purdie <rpurdie@linux.intel.com>
If we were to dynamically register/unregister leds and have udev or other
daemons handle the leds class uevents, we would be notified of the adding of a
new LED and if the daemon immediately tries to open one of the attributes of
the led device, it would fail with a "no such file or directory" error since
this the attributes are not yet created. Fix this by switching attributes to be
class-wide, such that the driver core will register these attributes with
device_add_attrs and then emit the kobject_uevent ADD signal.
Signed-off-by: Fainelli <ffainelli@freebox.fr>
Signed-off-by: Richard Purdie <rpurdie@linux.intel.com>
As each led device gets registered a kernel message gets printed. In
an embedded system with a number of leds this can produce a lot
of output that just looks like noise.
Change the message type to KERN_DEBUG since it might be useful
in the dmesg output "after" booting.
Signed-off-by: H Hartley Sweeten <hsweeten@visionengravers.com>
Signed-off-by: Richard Purdie <rpurdie@linux.intel.com>
Makes use of skip_spaces() defined in lib/string.c for removing leading
spaces from strings all over the tree.
It decreases lib.a code size by 47 bytes and reuses the function tree-wide:
text data bss dec hex filename
64688 584 592 65864 10148 (TOTALS-BEFORE)
64641 584 592 65817 10119 (TOTALS-AFTER)
Also, while at it, if we see (*str && isspace(*str)), we can be sure to
remove the first condition (*str) as the second one (isspace(*str)) also
evaluates to 0 whenever *str == 0, making it redundant. In other words,
"a char equals zero is never a space".
Julia Lawall tried the semantic patch (http://coccinelle.lip6.fr) below,
and found occurrences of this pattern on 3 more files:
drivers/leds/led-class.c
drivers/leds/ledtrig-timer.c
drivers/video/output.c
@@
expression str;
@@
( // ignore skip_spaces cases
while (*str && isspace(*str)) { \(str++;\|++str;\) }
|
- *str &&
isspace(*str)
)
Signed-off-by: André Goddard Rosa <andre.goddard@gmail.com>
Cc: Julia Lawall <julia@diku.dk>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Jeff Dike <jdike@addtoit.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Richard Purdie <rpurdie@rpsys.net>
Cc: Neil Brown <neilb@suse.de>
Cc: Kyle McMartin <kyle@mcmartin.ca>
Cc: Henrique de Moraes Holschuh <hmh@hmh.eng.br>
Cc: David Howells <dhowells@redhat.com>
Cc: <linux-ext4@vger.kernel.org>
Cc: Samuel Ortiz <samuel@sortiz.org>
Cc: Patrick McHardy <kaber@trash.net>
Cc: Takashi Iwai <tiwai@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This patch allows drivers to override the default maximum brightness value
of 255. We take care to preserve backwards-compatibility as much as
possible, so that user-space ABI doesn't change for existing drivers.
LED trigger code has also been updated to use the per-LED maximum.
Signed-off-by: Guennadi Liakhovetski <lg@denx.de>
Signed-off-by: Richard Purdie <rpurdie@linux.intel.com>
Add suspend/resume to the core class and remove all the now unneeded
code from various drivers. Originally the class code couldn't support
suspend/resume but since class_device can there is no reason for
each driver doing its own suspend/resume anymore.
Fix a race during trigger registration where we could try and use a lock
before it was initialised.
Signed-off-by: Richard Purdie <rpurdie@linux.intel.com>
led_classdev_unregister() has no "__" prefix, remove it.
Signed-off-by: Qinghuang Feng <qhfeng.kernel@gmail.com>
Signed-off-by: Richard Purdie <rpurdie@linux.intel.com>
There's no need for the additional call to strlen(), we can directly
return the value returned by sprintf(). We now return a length value
that doesn't include the final '\0', but user space shouldn't bother
about it anyway.
Signed-off-by: Sven Wegener <sven.wegener@stealer.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Richard Purdie <rpurdie@linux.intel.com>
