linux-toradex.git/drivers/leds/led-triggers.c, branch v4.16

leds: triggers: Check return value of kobject_uevent_env()

2016-09-20T08:22:10+00:00

Log error message if kobject_uevent_env() fails in led_trigger_set().

Signed-off-by: Jacek Anaszewski 
Acked-by: Greg Kroah-Hartman

leds: triggers: Return from led_trigger_set() if there is nothing to do

2016-09-20T08:21:17+00:00

If led_trigger_set() is called with "trig" argument set to NULL, and there
is no trigger to remove then the function should return immediately so
as to avoid doing unnecessary allocation and sending uevent.

Signed-off-by: Jacek Anaszewski 
Reported-by: Daniel Romell 
Acked-by Daniel Romell

leds: do not overflow sysfs buffer in led_trigger_show

2016-08-16T19:34:30+00:00

Per the documentation, use scnprintf instead of sprintf to ensure there
is never more than PAGE_SIZE bytes of trigger names put into the
buffer.

Signed-off-by: Nathan Sullivan 
Signed-off-by: Zach Brown 
Signed-off-by: Jacek Anaszewski

leds: make triggers explicitly non-modular

2016-08-16T19:19:06+00:00

The Kconfig currently controlling compilation of this code is:

drivers/leds/trigger/Kconfig:menuconfig LEDS_TRIGGERS
drivers/leds/trigger/Kconfig:   bool "LED Trigger support"

...meaning that it currently is not being built as a module by anyone.

Lets remove the couple traces of modular infrastructure use, so that
when reading the driver there is no doubt it is builtin-only.

We also delete the MODULE_LICENSE tag etc. since all that information
is already contained at the top of the file in the comments.

We don't replace module.h with init.h since the file doesn't need that.
However it does use EXPORT_SYMBOL, so we add the export.h header.

Cc: Richard Purdie 
Cc: linux-leds@vger.kernel.org
Signed-off-by: Paul Gortmaker 
Signed-off-by: Jacek Anaszewski

leds: triggers: return error if invalid trigger name is provided via sysfs

2016-07-04T06:51:37+00:00

If an invalid trigger name is provided via sysfs currently no error
is returned. Therefore it's not possible to determine whether the
trigger was set successfully.
Fix this by returning -EINVAL if no trigger is matched.

Signed-off-by: Heiner Kallweit 
Signed-off-by: Jacek Anaszewski

leds: triggers: Allow to switch the trigger to "panic" on a kernel panic

2016-05-06T08:22:09+00:00

This commit adds a new led_cdev flag LED_PANIC_INDICATOR, which
allows to mark a specific LED to be switched to the "panic"
trigger, on a kernel panic.

This is useful to allow the user to assign a regular trigger
to a given LED, and still blink that LED on a kernel panic.

Signed-off-by: Ezequiel Garcia 
Reviewed-by: Matthias Brugger 
Acked-by: Pavel Machek 
Signed-off-by: Jacek Anaszewski

leds: triggers: simplify led_trigger_store

2016-03-14T08:22:23+00:00

led_trigger_store can be significantly simplified by using sysfs_streq().

Signed-off-by: Heiner Kallweit 
Signed-off-by: Jacek Anaszewski

leds: core: add managed version of led_trigger_register

2016-01-04T08:57:40+00:00

Complementing devm_led_classdev_register add a managed version of
led_trigger_register.

I omit a managed version of led_classdev_unregister as the equivalent
devm_led_classdev_unregister isn't used in the kernel as of today.

Signed-off-by: Heiner Kallweit 
Signed-off-by: Jacek Anaszewski

leds: implement sysfs interface locking mechanism

2014-11-14T22:29:35+00:00

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 
Acked-by: Kyungmin Park 
Cc: Richard Purdie 
Signed-off-by: Bryan Wu

leds: make sure we unregister a trigger only once

2014-04-07T21:47:25+00:00

Currently, we may attempt to unregister a trigger more than once, for
example when we receive two consecutive reboot notifications, or when
we do a regular unregistration plus reboot notification.

This leads to the following error since we try to delete the list node
twice:

[ 2780.254922] WARNING: CPU: 0 PID: 13764 at lib/list_debug.c:53 __list_del_entry+0x3e/0xe0()
[ 2780.265559] list_del corruption, ffffffffa5eb6470->next is LIST_POISON1 (dead000000100100)
[ 2780.271710] Modules linked in:
[ 2780.274156] CPU: 0 PID: 13764 Comm: kworker/0:2 Tainted: G        W     3.14.0-next-20140403-sasha-00012-gef5fa7d-dirty #373
[ 2780.283063] Workqueue: events do_poweroff
[ 2780.285644]  0000000000000009 ffff8800330dbb38 ffffffffa34bfa33 0000000000002fe0
[ 2780.291571]  ffff8800330dbb88 ffff8800330dbb78 ffffffffa015a37c ffff8800330dbb68
[ 2780.296670]  ffffffffa5eb6470 0000000000000000 ffffffffa5eb6400 ffffffffa5ad7430
[ 2780.299756] Call Trace:
[ 2780.301530] dump_stack (lib/dump_stack.c:52)
[ 2780.303802] warn_slowpath_common (kernel/panic.c:418)
[ 2780.306151] warn_slowpath_fmt (kernel/panic.c:433)
[ 2780.308156] __list_del_entry (lib/list_debug.c:51 (discriminator 1))
[ 2780.310800] list_del (lib/list_debug.c:78)
[ 2780.313175] led_trigger_unregister (drivers/leds/led-triggers.c:225)
[ 2780.315599] heartbeat_reboot_notifier (drivers/leds/trigger/ledtrig-heartbeat.c:119)
[ 2780.317247] notifier_call_chain (kernel/notifier.c:95)
[ 2780.320014] __blocking_notifier_call_chain (kernel/notifier.c:316)
[ 2780.323263] blocking_notifier_call_chain (kernel/notifier.c:326)
[ 2780.326096] kernel_power_off (include/linux/kmod.h:95 kernel/reboot.c:153 kernel/reboot.c:179)
[ 2780.327883] do_poweroff (kernel/power/poweroff.c:23)
[ 2780.330748] process_one_work (kernel/workqueue.c:2221 include/linux/jump_label.h:105 include/trace/events/workqueue.h:111 kernel/workqueue.c:2226)
[ 2780.333027] ? process_one_work (include/linux/workqueue.h:186 kernel/workqueue.c:611 kernel/workqueue.c:638 kernel/workqueue.c:2214)
[ 2780.335487] process_scheduled_works (include/linux/list.h:188 kernel/workqueue.c:2277)
[ 2780.337101] worker_thread (kernel/workqueue.c:2352)
[ 2780.338712] ? rescuer_thread (kernel/workqueue.c:2297)
[ 2780.341326] kthread (kernel/kthread.c:219)
[ 2780.343446] ? kthread_create_on_node (kernel/kthread.c:185)
[ 2780.345733] ret_from_fork (arch/x86/kernel/entry_64.S:555)
[ 2780.347168] ? kthread_create_on_node (kernel/kthread.c:185)

Prevent it by making sure we don't attempt to unregister a trigger that
is not in the triggers list.

Signed-off-by: Sasha Levin 
Signed-off-by: Bryan Wu