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From: Sasha Levin <sashal@kernel.org>
To: linux-kernel@vger.kernel.org, stable@vger.kernel.org
Cc: Pavel Machek <pavel@ucw.cz>,
	Jacek Anaszewski <jacek.anaszewski@gmail.com>,
	Sasha Levin <sashal@kernel.org>,
	linux-leds@vger.kernel.org
Subject: [PATCH AUTOSEL 4.14 013/167] leds: avoid races with workqueue
Date: Wed, 22 May 2019 15:26:08 -0400	[thread overview]
Message-ID: <20190522192842.25858-13-sashal@kernel.org> (raw)
In-Reply-To: <20190522192842.25858-1-sashal@kernel.org>

From: Pavel Machek <pavel@ucw.cz>

[ Upstream commit 0db37915d912e8dc6588f25da76d3ed36718d92f ]

There are races between "main" thread and workqueue. They manifest
themselves on Thinkpad X60:

This should result in LED blinking, but it turns it off instead:

    root@amd:/data/pavel# cd /sys/class/leds/tpacpi\:\:power
    root@amd:/sys/class/leds/tpacpi::power# echo timer > trigger
    root@amd:/sys/class/leds/tpacpi::power# echo timer > trigger

It should be possible to transition from blinking to solid on by echo
0 > brightness; echo 1 > brightness... but that does not work, either,
if done too quickly.

Synchronization of the workqueue fixes both.

Fixes: 1afcadfcd184 ("leds: core: Use set_brightness_work for the blocking op")
Signed-off-by: Pavel Machek <pavel@ucw.cz>
Signed-off-by: Jacek Anaszewski <jacek.anaszewski@gmail.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 drivers/leds/led-class.c | 1 +
 drivers/leds/led-core.c  | 5 +++++
 2 files changed, 6 insertions(+)

diff --git a/drivers/leds/led-class.c b/drivers/leds/led-class.c
index b0e2d55acbd6f..80374c6c943ad 100644
--- a/drivers/leds/led-class.c
+++ b/drivers/leds/led-class.c
@@ -57,6 +57,7 @@ static ssize_t brightness_store(struct device *dev,
 	if (state == LED_OFF)
 		led_trigger_remove(led_cdev);
 	led_set_brightness(led_cdev, state);
+	flush_work(&led_cdev->set_brightness_work);
 
 	ret = size;
 unlock:
diff --git a/drivers/leds/led-core.c b/drivers/leds/led-core.c
index 9ce6b32f52a19..cb84c35d64f97 100644
--- a/drivers/leds/led-core.c
+++ b/drivers/leds/led-core.c
@@ -162,6 +162,11 @@ 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))
-- 
2.20.1


  parent reply	other threads:[~2019-05-22 19:41 UTC|newest]

Thread overview: 62+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2019-05-22 19:25 [PATCH AUTOSEL 4.14 001/167] gfs2: Fix lru_count going negative Sasha Levin
2019-05-22 19:25 ` [PATCH AUTOSEL 4.14 002/167] cxgb4: Fix error path in cxgb4_init_module Sasha Levin
2019-05-22 19:25 ` [PATCH AUTOSEL 4.14 003/167] NFS: make nfs_match_client killable Sasha Levin
2019-05-22 19:25 ` [PATCH AUTOSEL 4.14 004/167] IB/hfi1: Fix WQ_MEM_RECLAIM warning Sasha Levin
2019-05-22 19:26 ` [PATCH AUTOSEL 4.14 005/167] gfs2: Fix occasional glock use-after-free Sasha Levin
2019-05-22 19:26 ` [PATCH AUTOSEL 4.14 006/167] mmc: core: Verify SD bus width Sasha Levin
2019-05-22 19:26 ` [PATCH AUTOSEL 4.14 007/167] tools/bpf: fix perf build error with uClibc (seen on ARC) Sasha Levin
2019-05-22 19:26 ` [PATCH AUTOSEL 4.14 008/167] dmaengine: tegra210-dma: free dma controller in remove() Sasha Levin
2019-05-22 19:26 ` [PATCH AUTOSEL 4.14 009/167] net: ena: gcc 8: fix compilation warning Sasha Levin
2019-05-22 19:26 ` [PATCH AUTOSEL 4.14 010/167] orangefs: truncate before updating size Sasha Levin
2019-05-22 19:26 ` [PATCH AUTOSEL 4.14 011/167] pinctrl: zte: fix leaked of_node references Sasha Levin
2019-05-22 19:26 ` [PATCH AUTOSEL 4.14 012/167] ASoC: hdmi-codec: unlock the device on startup errors Sasha Levin
2019-05-22 19:26 ` Sasha Levin [this message]
2019-05-22 19:26 ` [PATCH AUTOSEL 4.14 014/167] powerpc/perf: Return accordingly on invalid chip-id in Sasha Levin
2019-05-22 19:26 ` [PATCH AUTOSEL 4.14 015/167] powerpc/boot: Fix missing check of lseek() return value Sasha Levin
2019-05-22 19:26 ` [PATCH AUTOSEL 4.14 016/167] ASoC: imx: fix fiq dependencies Sasha Levin
2019-05-22 19:26 ` [PATCH AUTOSEL 4.14 017/167] spi: pxa2xx: fix SCR (divisor) calculation Sasha Levin
2019-05-22 19:26 ` [PATCH AUTOSEL 4.14 018/167] brcm80211: potential NULL dereference in brcmf_cfg80211_vndr_cmds_dcmd_handler() Sasha Levin
2019-05-22 19:26 ` [PATCH AUTOSEL 4.14 019/167] ACPI / property: fix handling of data_nodes in acpi_get_next_subnode() Sasha Levin
2019-05-22 19:26 ` [PATCH AUTOSEL 4.14 020/167] ARM: vdso: Remove dependency with the arch_timer driver internals Sasha Levin
2019-05-22 19:26 ` [PATCH AUTOSEL 4.14 021/167] arm64: Fix compiler warning from pte_unmap() with -Wunused-but-set-variable Sasha Levin
2019-05-22 19:26 ` [PATCH AUTOSEL 4.14 022/167] sched/cpufreq: Fix kobject memleak Sasha Levin
2019-05-22 19:26 ` [PATCH AUTOSEL 4.14 023/167] scsi: qla2xxx: Fix a qla24xx_enable_msix() error path Sasha Levin
2019-05-22 19:26 ` [PATCH AUTOSEL 4.14 024/167] scsi: qla2xxx: Fix abort handling in tcm_qla2xxx_write_pending() Sasha Levin
2019-05-22 19:26 ` [PATCH AUTOSEL 4.14 025/167] scsi: qla2xxx: Avoid that lockdep complains about unsafe locking in tcm_qla2xxx_close_session() Sasha Levin
2019-05-22 19:26 ` [PATCH AUTOSEL 4.14 026/167] Btrfs: fix data bytes_may_use underflow with fallocate due to failed quota reserve Sasha Levin
2019-05-22 19:26 ` [PATCH AUTOSEL 4.14 027/167] btrfs: fix panic during relocation after ENOSPC before writeback happens Sasha Levin
2019-05-22 19:26 ` [PATCH AUTOSEL 4.14 028/167] btrfs: Don't panic when we can't find a root key Sasha Levin
2019-05-22 19:26 ` [PATCH AUTOSEL 4.14 029/167] iwlwifi: pcie: don't crash on invalid RX interrupt Sasha Levin
2019-05-22 19:26 ` [PATCH AUTOSEL 4.14 030/167] rtc: 88pm860x: prevent use-after-free on device remove Sasha Levin
2019-05-22 19:26 ` [PATCH AUTOSEL 4.14 031/167] scsi: qedi: Abort ep termination if offload not scheduled Sasha Levin
2019-05-22 19:26 ` [PATCH AUTOSEL 4.14 032/167] w1: fix the resume command API Sasha Levin
2019-05-22 19:26 ` [PATCH AUTOSEL 4.14 033/167] dmaengine: pl330: _stop: clear interrupt status Sasha Levin
2019-05-22 19:26 ` [PATCH AUTOSEL 4.14 034/167] mac80211/cfg80211: update bss channel on channel switch Sasha Levin
2019-05-22 19:26 ` [PATCH AUTOSEL 4.14 035/167] libbpf: fix samples/bpf build failure due to undefined UINT32_MAX Sasha Levin
2019-05-22 19:26 ` [PATCH AUTOSEL 4.14 036/167] driver core: platform: Fix the usage of platform device name(pdev->name) Sasha Levin
2019-05-22 20:05   ` Greg Kroah-Hartman
2019-05-22 19:26 ` [PATCH AUTOSEL 4.14 037/167] ASoC: fsl_sai: Update is_slave_mode with correct value Sasha Levin
2019-05-22 19:26 ` [PATCH AUTOSEL 4.14 038/167] mwifiex: prevent an array overflow Sasha Levin
2019-05-22 19:26 ` [PATCH AUTOSEL 4.14 039/167] net: cw1200: fix a NULL pointer dereference Sasha Levin
2019-05-22 19:26 ` [PATCH AUTOSEL 4.14 040/167] at76c50x-usb: Don't register led_trigger if usb_register_driver failed Sasha Levin
2019-05-22 19:26 ` [PATCH AUTOSEL 4.14 041/167] ssb: Fix possible NULL pointer dereference in ssb_host_pcmcia_exit Sasha Levin
2019-05-22 19:26 ` [PATCH AUTOSEL 4.14 042/167] crypto: sun4i-ss - Fix invalid calculation of hash end Sasha Levin
2019-05-22 19:26 ` [PATCH AUTOSEL 4.14 043/167] bcache: return error immediately in bch_journal_replay() Sasha Levin
2019-05-22 19:26 ` [PATCH AUTOSEL 4.14 044/167] bcache: fix failure in journal relplay Sasha Levin
2019-05-22 19:26 ` [PATCH AUTOSEL 4.14 045/167] bcache: add failure check to run_cache_set() for journal replay Sasha Levin
2019-05-22 19:26 ` [PATCH AUTOSEL 4.14 046/167] bcache: avoid clang -Wunintialized warning Sasha Levin
2019-05-22 19:26 ` [PATCH AUTOSEL 4.14 047/167] RDMA/cma: Consider scope_id while binding to ipv6 ll address Sasha Levin
2019-05-22 19:26 ` [PATCH AUTOSEL 4.14 048/167] vfio-ccw: Do not call flush_workqueue while holding the spinlock Sasha Levin
2019-05-22 19:26 ` [PATCH AUTOSEL 4.14 049/167] vfio-ccw: Release any channel program when releasing/removing vfio-ccw mdev Sasha Levin
2019-05-22 19:26 ` [PATCH AUTOSEL 4.14 050/167] x86/build: Move _etext to actual end of .text Sasha Levin
2019-05-22 19:26 ` [PATCH AUTOSEL 4.14 051/167] smpboot: Place the __percpu annotation correctly Sasha Levin
2019-05-22 19:26 ` [PATCH AUTOSEL 4.14 052/167] x86/mm: Remove in_nmi() warning from 64-bit implementation of vmalloc_fault() Sasha Levin
2019-05-22 19:26 ` [PATCH AUTOSEL 4.14 053/167] mm/uaccess: Use 'unsigned long' to placate UBSAN warnings on older GCC versions Sasha Levin
2019-05-22 19:26 ` [PATCH AUTOSEL 4.14 054/167] HID: logitech-hidpp: use RAP instead of FAP to get the protocol version Sasha Levin
2019-05-22 19:26 ` [PATCH AUTOSEL 4.14 055/167] pinctrl: pistachio: fix leaked of_node references Sasha Levin
2019-05-22 19:26 ` [PATCH AUTOSEL 4.14 056/167] pinctrl: samsung: " Sasha Levin
2019-05-22 19:26 ` [PATCH AUTOSEL 4.14 057/167] clk: rockchip: undo several noc and special clocks as critical on rk3288 Sasha Levin
2019-05-22 19:26 ` [PATCH AUTOSEL 4.14 058/167] dmaengine: at_xdmac: remove BUG_ON macro in tasklet Sasha Levin
2019-05-22 19:26 ` [PATCH AUTOSEL 4.14 059/167] media: coda: clear error return value before picture run Sasha Levin
2019-05-22 19:26 ` [PATCH AUTOSEL 4.14 060/167] media: ov6650: Move v4l2_clk_get() to ov6650_video_probe() helper Sasha Levin
2019-05-22 19:26 ` [PATCH AUTOSEL 4.14 061/167] media: au0828: stop video streaming only when last user stops Sasha Levin

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