From 8c0f693c6effbc3f42f77a9e81209af9af20910c Mon Sep 17 00:00:00 2001
From: Pavel Machek <pavel@ucw.cz>
Date: Sun, 26 May 2019 09:38:55 +0200
Subject: [PATCH] leds: avoid flush_work in atomic context
It turns out that various triggers use led_blink_setup() from atomic
context, so we can't do a flush_work there. Flush is still needed for
slow LEDs, but we can move it to sysfs code where it is safe.
WARNING: inconsistent lock state
5.2.0-rc1 #1 Tainted: G W
--------------------------------
inconsistent {SOFTIRQ-ON-W} -> {IN-SOFTIRQ-W} usage.
swapper/1/0 [HC0[0]:SC1[1]:HE1:SE0] takes:
000000006e30541b
((work_completion)(&led_cdev->set_brightness_work)){+.?.}, at:
+__flush_work+0x3b/0x38a
{SOFTIRQ-ON-W} state was registered at:
lock_acquire+0x146/0x1a1
__flush_work+0x5b/0x38a
flush_work+0xb/0xd
led_blink_setup+0x1e/0xd3
led_blink_set+0x3f/0x44
tpt_trig_timer+0xdb/0x106
ieee80211_mod_tpt_led_trig+0xed/0x112
Fixes: 0db37915d912 ("leds: avoid races with workqueue")
Signed-off-by: Pavel Machek <pavel@ucw.cz>
Tested-by: Hugh Dickins <hughd@google.com>
Signed-off-by: Jacek Anaszewski <jacek.anaszewski@gmail.com>
---
drivers/leds/led-core.c | 5 -----
drivers/leds/trigger/ledtrig-timer.c | 5 +++++
2 files changed, 5 insertions(+), 5 deletions(-)
diff --git a/drivers/leds/led-core.c b/drivers/leds/led-core.c
index e9ae7f87ab900..e3da7c03da1b5 100644
--- a/drivers/leds/led-core.c
+++ b/drivers/leds/led-core.c
@@ -164,11 +164,6 @@ static void led_blink_setup(struct led_classdev *led_cdev,
unsigned long *delay_on,
unsigned long *delay_off)
{
- /*
- * If "set brightness to 0" is pending in workqueue, we don't
- * want that to be reordered after blink_set()
- */
- flush_work(&led_cdev->set_brightness_work);
if (!test_bit(LED_BLINK_ONESHOT, &led_cdev->work_flags) &&
led_cdev->blink_set &&
!led_cdev->blink_set(led_cdev, delay_on, delay_off))
diff --git a/drivers/leds/trigger/ledtrig-timer.c b/drivers/leds/trigger/ledtrig-timer.c
index ca898c1383bee..427fc3c303d5a 100644
--- a/drivers/leds/trigger/ledtrig-timer.c
+++ b/drivers/leds/trigger/ledtrig-timer.c
@@ -113,6 +113,11 @@ static int timer_trig_activate(struct led_classdev *led_cdev)
led_cdev->flags &= ~LED_INIT_DEFAULT_TRIGGER;
}
+ /*
+ * If "set brightness to 0" is pending in workqueue, we don't
+ * want that to be reordered after blink_set()
+ */
+ flush_work(&led_cdev->set_brightness_work);
led_blink_set(led_cdev, &led_cdev->blink_delay_on,
&led_cdev->blink_delay_off);
--
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