03 Sep, 2014
1 commit
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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+0xa5/0xb0other 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+0xf1/0xf4Cc: Vincent Donnefort
Cc: Hugh Dickins
Cc: Tejun Heo
Signed-off-by: Jiri Kosina
Signed-off-by: Bryan Wu
04 Jul, 2014
1 commit
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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
28 Feb, 2014
1 commit
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When using the timer trigger and setting delay_on to 0, the led
will stay in whatever state is was in, while intuitively one
would expect it to turn off. This patch changes the behaviour to
turn it off.Signed-off-by: Stefan Sørensen
Signed-off-by: Bryan Wu
11 Sep, 2012
1 commit
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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
Cc: Pawel Moll
Signed-off-by: Bryan Wu
24 Jul, 2012
5 commits
-
drivers/leds/led-core.c:56:6: sparse: symbol 'led_blink_setup' was not declared. Should it be static?
drivers/leds/led-triggers.c:233:6: sparse: symbol 'led_trigger_blink_setup' was not declared. Should it be static?Reported-by: Fengguang Wu
Signed-off-by: Bryan Wu -
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
Signed-off-by: Bryan Wu -
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
Signed-off-by: Bryan Wu -
Move led_stop_software_blink() code into led_brightness_set() to ensure
software blink timer is stopped and cleared when changing trigger.Also use led_set_brightness() instead of calling
led_cdev->brightness_set() directly to keep led_cdev->brightness
consistent with current LED status.This ensure proper cleaning when changing triggers, as without this fix
a LED may be turned off while leaving it's led_cdev->brightness = 1,
leading to an erratic software-blink behaviour.The problem was easy to reproduce by changing the trigger from "timer"
to "oneshot".Signed-off-by: Fabio Baltieri
Signed-off-by: Bryan Wu -
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
Acked-by: Shuah Khan
Signed-off-by: Bryan Wu
12 Jun, 2012
1 commit
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Function led_set_software_blink() assumes that blink timer is still running,
but commit 488bc35bf40df89d37486c1826b178a2fba36ce7 introduced disabling
of blink timer before each call to led_set_software_blink().Correct led_software_blink():
1) remove protection against reprogramming blink timer to the same values,
because it only disables blinking now,
2) remove unnecessary call to led_stop_software_blink().Signed-off-by: Rafal Prylowski
Cc: Richard Purdie
Signed-off-by: Bryan Wu
24 Mar, 2012
1 commit
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After moving some core functions to led-core.c, led-class.c can be built
as module again.Signed-off-by: Bryan Wu
Acked-by: Richard Purdie
Acked-by: Linus Walleij
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds