kernel.git/drivers/leds/led-core.c, branch linux-4.4.y

Revert "led: core: Fix brightness setting when setting delay_off=0"

2018-03-11T15:19:45Z

This reverts commit 20ac8f72514b3af8b62c520d55656ded865eff00, which was commit 2b83ff96f51d0b039c4561b9f95c824d7bddb85c upstream. The bug that it should fix was only introduced in Linux 4.7, and in 4.4 it causes a regression. Reported-by: Jacek Anaszewski Cc: Matthieu CASTET Signed-off-by: Ben Hutchings Signed-off-by: Greg Kroah-Hartman

led: core: Fix brightness setting when setting delay_off=0

2018-03-03T09:19:43Z

[ Upstream commit 2b83ff96f51d0b039c4561b9f95c824d7bddb85c ] With the current code, the following sequence won't work : echo timer > trigger echo 0 > delay_off * at this point we call ** led_delay_off_store ** led_blink_set

leds: core: Move LED core callbacks out of led-class.c

2015-11-03T07:59:22Z

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 Acked-by: Andrew Lunn Acked-by: Pavel Machek

leds: fix brightness changing when software blinking is active

2015-05-25T20:26:47Z

The following sequence: echo timer >/sys/class/leds//trigger echo 1 >/sys/class/leds//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 CC: Kyungmin Park CC: linux-leds@vger.kernel.org CC: linux-kernel@vger.kernel.org Acked-by: Jacek Anaszewski Signed-off-by: Stas Sergeev Signed-off-by: Bryan Wu

leds: Add support for setting brightness in a synchronous way

2014-11-14T22:29:35Z

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

leds: implement sysfs interface locking mechanism

2014-11-14T22:29:35Z

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: Improve and export led_update_brightness

2014-09-12T21:01:54Z

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

leds: Reorder include directives

2014-09-11T23:55:25Z

Reorder include directives so that they are arranged in alphabetical order. Signed-off-by: Jacek Anaszewski Acked-by: Kyungmin Park Cc: Richard Purdie Signed-off-by: Bryan Wu

Revert "leds: convert blink timer to workqueue"

2014-09-02T17:02:13Z

This reverts commit 8b37e1bef5a6b60e949e28a4db3006e4b00bd758. It's broken as it changes led_blink_set() in a way that it can now sleep (while synchronously waiting for workqueue to be cancelled). That's a problem, because it's possible that this function gets called from atomic context (tpt_trig_timer() takes a readlock and thus disables preemption). This has been brought up 3 weeks ago already [1] but no proper fix has materialized, and I keep seeing the problem since 3.17-rc1. [1] https://lkml.org/lkml/2014/8/16/128 BUG: sleeping function called from invalid context at kernel/workqueue.c:2650 in_atomic(): 1, irqs_disabled(): 0, pid: 2335, name: wpa_supplicant 5 locks held by wpa_supplicant/2335: #0: (rtnl_mutex){+.+.+.}, at: [] rtnl_lock+0x12/0x20 #1: (&wdev->mtx){+.+.+.}, at: [] cfg80211_mgd_wext_siwessid+0x5c/0x180 [cfg80211] #2: (&local->mtx){+.+.+.}, at: [] ieee80211_prep_connection+0x17a/0x9a0 [mac80211] #3: (&local->chanctx_mtx){+.+.+.}, at: [] ieee80211_vif_use_channel+0x5d/0x2a0 [mac80211] #4: (&trig->leddev_list_lock){.+.+..}, at: [] tpt_trig_timer+0xec/0x170 [mac80211] CPU: 0 PID: 2335 Comm: wpa_supplicant Not tainted 3.17.0-rc3 #1 Hardware name: LENOVO 7470BN2/7470BN2, BIOS 6DET38WW (2.02 ) 12/19/2008 ffff8800360b5a50 ffff8800751f76d8 ffffffff8159e97f ffff8800360b5a30 ffff8800751f76e8 ffffffff810739a5 ffff8800751f77b0 ffffffff8106862f ffffffff810685d0 0aa2209200000000 ffff880000000004 ffff8800361c59d0 Call Trace: [] dump_stack+0x4d/0x66 [] __might_sleep+0xe5/0x120 [] flush_work+0x5f/0x270 [] ? mod_delayed_work_on+0x80/0x80 [] ? mark_held_locks+0x6a/0x90 [] ? __cancel_work_timer+0x6f/0x100 [] ? trace_hardirqs_on_caller+0xfd/0x1c0 [] __cancel_work_timer+0x7b/0x100 [] cancel_delayed_work_sync+0xe/0x10 [] led_blink_set+0x1b/0x40 [] tpt_trig_timer+0x110/0x170 [mac80211] [] ieee80211_mod_tpt_led_trig+0x9d/0x160 [mac80211] [] __ieee80211_recalc_idle+0x98/0x140 [mac80211] [] ieee80211_idle_off+0xe/0x10 [mac80211] [] ieee80211_add_chanctx+0x3b/0x220 [mac80211] [] ieee80211_new_chanctx+0x44/0xf0 [mac80211] [] ieee80211_vif_use_channel+0x1fa/0x2a0 [mac80211] [] ieee80211_prep_connection+0x188/0x9a0 [mac80211] [] ieee80211_mgd_auth+0x256/0x2e0 [mac80211] [] ieee80211_auth+0x13/0x20 [mac80211] [] cfg80211_mlme_auth+0x106/0x270 [cfg80211] [] cfg80211_conn_do_work+0x155/0x3b0 [cfg80211] [] cfg80211_connect+0x3f0/0x540 [cfg80211] [] cfg80211_mgd_wext_connect+0x158/0x1f0 [cfg80211] [] cfg80211_mgd_wext_siwessid+0xde/0x180 [cfg80211] [] ? cfg80211_wext_giwessid+0x50/0x50 [cfg80211] [] cfg80211_wext_siwessid+0x1d/0x40 [cfg80211] [] ioctl_standard_iw_point+0x14c/0x3e0 [] ? trace_hardirqs_on_caller+0xfd/0x1c0 [] ioctl_standard_call+0x8a/0xd0 [] ? ioctl_standard_iw_point+0x3e0/0x3e0 [] wireless_process_ioctl.constprop.10+0xb6/0x100 [] wext_handle_ioctl+0x5d/0xb0 [] dev_ioctl+0x329/0x620 [] ? trace_hardirqs_on_caller+0xfd/0x1c0 [] sock_ioctl+0x142/0x2e0 [] do_vfs_ioctl+0x300/0x520 [] ? sysret_check+0x1b/0x56 [] ? trace_hardirqs_on_caller+0xfd/0x1c0 [] SyS_ioctl+0x81/0xa0 [] system_call_fastpath+0x1a/0x1f wlan0: send auth to 00:0b:6b:3c:8c:e4 (try 1/3) wlan0: authenticated wlan0: associate with 00:0b:6b:3c:8c:e4 (try 1/3) wlan0: RX AssocResp from 00:0b:6b:3c:8c:e4 (capab=0x431 status=0 aid=2) wlan0: associated IPv6: ADDRCONF(NETDEV_CHANGE): wlan0: link becomes ready cfg80211: Calling CRDA for country: NA wlan0: Limiting TX power to 27 (27 - 0) dBm as advertised by 00:0b:6b:3c:8c:e4 ================================= [ INFO: inconsistent lock state ] 3.17.0-rc3 #1 Not tainted --------------------------------- inconsistent {SOFTIRQ-ON-W} -> {IN-SOFTIRQ-W} usage. swapper/0/0 [HC0[0]:SC1[1]:HE1:SE0] takes: ((&(&led_cdev->blink_work)->work)){+.?...}, at: [] flush_work+0x0/0x270 {SOFTIRQ-ON-W} state was registered at: [] __lock_acquire+0x30e/0x1a30 [] lock_acquire+0x91/0x110 [] flush_work+0x38/0x270 [] __cancel_work_timer+0x7b/0x100 [] cancel_delayed_work_sync+0xe/0x10 [] led_blink_set+0x1b/0x40 [] tpt_trig_timer+0x110/0x170 [mac80211] [] ieee80211_mod_tpt_led_trig+0x9d/0x160 [mac80211] [] __ieee80211_recalc_idle+0x98/0x140 [mac80211] [] ieee80211_idle_off+0xe/0x10 [mac80211] [] ieee80211_add_chanctx+0x3b/0x220 [mac80211] [] ieee80211_new_chanctx+0x44/0xf0 [mac80211] [] ieee80211_vif_use_channel+0x1fa/0x2a0 [mac80211] [] ieee80211_prep_connection+0x188/0x9a0 [mac80211] [] ieee80211_mgd_auth+0x256/0x2e0 [mac80211] [] ieee80211_auth+0x13/0x20 [mac80211] [] cfg80211_mlme_auth+0x106/0x270 [cfg80211] [] cfg80211_conn_do_work+0x155/0x3b0 [cfg80211] [] cfg80211_connect+0x3f0/0x540 [cfg80211] [] cfg80211_mgd_wext_connect+0x158/0x1f0 [cfg80211] [] cfg80211_mgd_wext_siwessid+0xde/0x180 [cfg80211] [] cfg80211_wext_siwessid+0x1d/0x40 [cfg80211] [] ioctl_standard_iw_point+0x14c/0x3e0 [] ioctl_standard_call+0x8a/0xd0 [] wireless_process_ioctl.constprop.10+0xb6/0x100 [] wext_handle_ioctl+0x5d/0xb0 [] dev_ioctl+0x329/0x620 [] sock_ioctl+0x142/0x2e0 [] do_vfs_ioctl+0x300/0x520 [] SyS_ioctl+0x81/0xa0 [] system_call_fastpath+0x1a/0x1f irq event stamp: 493416 hardirqs last enabled at (493416): [] __cancel_work_timer+0x6f/0x100 hardirqs last disabled at (493415): [] try_to_grab_pending+0x1f/0x160 softirqs last enabled at (493408): [] _local_bh_enable+0x1d/0x50 softirqs last disabled at (493409): [] irq_exit+0xa5/0xb0 other info that might help us debug this: Possible unsafe locking scenario: CPU0 ---- lock((&(&led_cdev->blink_work)->work)); lock((&(&led_cdev->blink_work)->work)); *** DEADLOCK *** 2 locks held by swapper/0/0: #0: (((&tpt_trig->timer))){+.-...}, at: [] call_timer_fn+0x0/0x180 #1: (&trig->leddev_list_lock){.+.?..}, at: [] tpt_trig_timer+0xec/0x170 [mac80211] stack backtrace: CPU: 0 PID: 0 Comm: swapper/0 Not tainted 3.17.0-rc3 #1 Hardware name: LENOVO 7470BN2/7470BN2, BIOS 6DET38WW (2.02 ) 12/19/2008 ffffffff8246eb30 ffff88007c203b00 ffffffff8159e97f ffffffff81a194c0 ffff88007c203b50 ffffffff81599c29 0000000000000001 ffffffff00000001 ffff880000000000 0000000000000006 ffffffff81a194c0 ffffffff81093ad0 Call Trace: [] dump_stack+0x4d/0x66 [] print_usage_bug+0x1f4/0x205 [] ? check_usage_backwards+0x140/0x140 [] mark_lock+0x223/0x2b0 [] __lock_acquire+0x2b0/0x1a30 [] lock_acquire+0x91/0x110 [] ? mod_delayed_work_on+0x80/0x80 [] ? __ieee80211_get_rx_led_name+0x10/0x10 [mac80211] [] flush_work+0x38/0x270 [] ? mod_delayed_work_on+0x80/0x80 [] ? mark_held_locks+0x6a/0x90 [] ? __cancel_work_timer+0x6f/0x100 [] ? __ieee80211_get_rx_led_name+0x10/0x10 [mac80211] [] ? trace_hardirqs_on_caller+0xad/0x1c0 [] ? __ieee80211_get_rx_led_name+0x10/0x10 [mac80211] [] __cancel_work_timer+0x7b/0x100 [] cancel_delayed_work_sync+0xe/0x10 [] led_blink_set+0x1b/0x40 [] tpt_trig_timer+0x110/0x170 [mac80211] [] call_timer_fn+0x75/0x180 [] ? process_timeout+0x10/0x10 [] ? __ieee80211_get_rx_led_name+0x10/0x10 [mac80211] [] run_timer_softirq+0x1fc/0x2f0 [] __do_softirq+0x115/0x2e0 [] irq_exit+0xa5/0xb0 [] do_IRQ+0x53/0xf0 [] common_interrupt+0x6f/0x6f [] ? cpuidle_enter_state+0x6e/0x180 [] cpuidle_enter+0x12/0x20 [] cpu_startup_entry+0x330/0x360 [] rest_init+0xc1/0xd0 [] ? csum_partial_copy_generic+0x170/0x170 [] start_kernel+0x44f/0x45a [] ? set_init_arg+0x53/0x53 [] x86_64_start_reservations+0x2a/0x2c [] x86_64_start_kernel+0xf1/0xf4 Cc: Vincent Donnefort Cc: Hugh Dickins Cc: Tejun Heo Signed-off-by: Jiri Kosina Signed-off-by: Bryan Wu

leds: convert blink timer to workqueue

2014-07-03T19:02:14Z

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 Signed-off-by: Bryan Wu