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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 4.19 021/244] leds: avoid races with workqueue
Date: Wed, 22 May 2019 15:22:47 -0400	[thread overview]
Message-ID: <20190522192630.24917-21-sashal@kernel.org> (raw)
In-Reply-To: <20190522192630.24917-1-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 3c7e3487b373b..85848c5da705f 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 ede4fa0ac2cce..55dec67023599 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 19:27 UTC|newest]

Thread overview: 84+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2019-05-22 19:22 [PATCH AUTOSEL 4.19 001/244] gfs2: Fix lru_count going negative Sasha Levin
2019-05-22 19:22 ` [PATCH AUTOSEL 4.19 002/244] cxgb4: Fix error path in cxgb4_init_module Sasha Levin
2019-05-22 19:22 ` [PATCH AUTOSEL 4.19 003/244] NFS: make nfs_match_client killable Sasha Levin
2019-05-22 19:22 ` [PATCH AUTOSEL 4.19 004/244] IB/hfi1: Fix WQ_MEM_RECLAIM warning Sasha Levin
2019-05-22 19:22 ` [PATCH AUTOSEL 4.19 005/244] gfs2: Fix occasional glock use-after-free Sasha Levin
2019-05-22 19:22 ` [PATCH AUTOSEL 4.19 006/244] mmc: core: Verify SD bus width Sasha Levin
2019-05-22 19:22 ` [PATCH AUTOSEL 4.19 007/244] batman-adv: mcast: fix multicast tt/tvlv worker locking Sasha Levin
2019-05-22 19:22 ` [PATCH AUTOSEL 4.19 008/244] tools/bpf: fix perf build error with uClibc (seen on ARC) Sasha Levin
2019-05-22 19:22 ` [PATCH AUTOSEL 4.19 009/244] selftests/bpf: set RLIMIT_MEMLOCK properly for test_libbpf_open.c Sasha Levin
2019-05-22 19:22 ` [PATCH AUTOSEL 4.19 010/244] bpftool: exclude bash-completion/bpftool from .gitignore pattern Sasha Levin
2019-05-22 19:22 ` [PATCH AUTOSEL 4.19 011/244] dmaengine: tegra210-dma: free dma controller in remove() Sasha Levin
2019-05-22 19:22 ` [PATCH AUTOSEL 4.19 012/244] net: ena: gcc 8: fix compilation warning Sasha Levin
2019-05-22 19:22 ` [PATCH AUTOSEL 4.19 013/244] hv_netvsc: fix race that may miss tx queue wakeup Sasha Levin
2019-05-22 19:22 ` [PATCH AUTOSEL 4.19 014/244] orangefs: truncate before updating size Sasha Levin
2019-05-22 19:22 ` [PATCH AUTOSEL 4.19 015/244] Bluetooth: Ignore CC events not matching the last HCI command Sasha Levin
2019-05-22 19:22 ` [PATCH AUTOSEL 4.19 016/244] pinctrl: zte: fix leaked of_node references Sasha Levin
2019-05-22 19:22 ` [PATCH AUTOSEL 4.19 017/244] ASoC: Intel: kbl_da7219_max98357a: Map BTN_0 to KEY_PLAYPAUSE Sasha Levin
2019-05-22 19:22 ` [PATCH AUTOSEL 4.19 018/244] usb: dwc2: gadget: Increase descriptors count for ISOC's Sasha Levin
2019-05-22 19:22 ` [PATCH AUTOSEL 4.19 019/244] usb: dwc3: move synchronize_irq() out of the spinlock protected block Sasha Levin
2019-05-22 19:22 ` [PATCH AUTOSEL 4.19 020/244] ASoC: hdmi-codec: unlock the device on startup errors Sasha Levin
2019-05-22 19:22 ` Sasha Levin [this message]
2019-05-22 19:22 ` [PATCH AUTOSEL 4.19 022/244] powerpc/perf: Return accordingly on invalid chip-id in Sasha Levin
2019-05-22 19:22 ` [PATCH AUTOSEL 4.19 023/244] powerpc/boot: Fix missing check of lseek() return value Sasha Levin
2019-05-22 19:22 ` [PATCH AUTOSEL 4.19 024/244] powerpc/perf: Fix loop exit condition in nest_imc_event_init Sasha Levin
2019-05-22 19:22 ` [PATCH AUTOSEL 4.19 025/244] ASoC: imx: fix fiq dependencies Sasha Levin
2019-05-22 19:22 ` [PATCH AUTOSEL 4.19 026/244] spi: pxa2xx: fix SCR (divisor) calculation Sasha Levin
2019-05-22 19:22 ` [PATCH AUTOSEL 4.19 027/244] brcm80211: potential NULL dereference in brcmf_cfg80211_vndr_cmds_dcmd_handler() Sasha Levin
2019-05-22 19:22 ` [PATCH AUTOSEL 4.19 028/244] ACPI / property: fix handling of data_nodes in acpi_get_next_subnode() Sasha Levin
2019-05-22 19:22 ` [PATCH AUTOSEL 4.19 029/244] drm/nouveau/bar/nv50: ensure BAR is mapped Sasha Levin
2019-05-22 19:22 ` [PATCH AUTOSEL 4.19 030/244] media: stm32-dcmi: return appropriate error codes during probe Sasha Levin
2019-05-22 19:22 ` [PATCH AUTOSEL 4.19 031/244] ARM: vdso: Remove dependency with the arch_timer driver internals Sasha Levin
2019-05-22 19:22 ` [PATCH AUTOSEL 4.19 032/244] arm64: Fix compiler warning from pte_unmap() with -Wunused-but-set-variable Sasha Levin
2019-05-22 19:22 ` [PATCH AUTOSEL 4.19 033/244] powerpc/watchdog: Use hrtimers for per-CPU heartbeat Sasha Levin
2019-05-22 19:23 ` [PATCH AUTOSEL 4.19 034/244] sched/cpufreq: Fix kobject memleak Sasha Levin
2019-05-22 19:23 ` [PATCH AUTOSEL 4.19 035/244] scsi: qla2xxx: Fix a qla24xx_enable_msix() error path Sasha Levin
2019-05-22 19:23 ` [PATCH AUTOSEL 4.19 036/244] scsi: qla2xxx: Fix abort handling in tcm_qla2xxx_write_pending() Sasha Levin
2019-05-22 19:23 ` [PATCH AUTOSEL 4.19 037/244] scsi: qla2xxx: Avoid that lockdep complains about unsafe locking in tcm_qla2xxx_close_session() Sasha Levin
2019-05-22 19:23 ` [PATCH AUTOSEL 4.19 038/244] scsi: qla2xxx: Fix hardirq-unsafe locking Sasha Levin
2019-05-22 19:23 ` [PATCH AUTOSEL 4.19 039/244] x86/modules: Avoid breaking W^X while loading modules Sasha Levin
2019-05-22 19:23 ` [PATCH AUTOSEL 4.19 040/244] Btrfs: fix data bytes_may_use underflow with fallocate due to failed quota reserve Sasha Levin
2019-05-22 19:23 ` [PATCH AUTOSEL 4.19 041/244] btrfs: fix panic during relocation after ENOSPC before writeback happens Sasha Levin
2019-05-22 19:23 ` [PATCH AUTOSEL 4.19 042/244] btrfs: Don't panic when we can't find a root key Sasha Levin
2019-05-22 19:23 ` [PATCH AUTOSEL 4.19 043/244] iwlwifi: pcie: don't crash on invalid RX interrupt Sasha Levin
2019-05-22 19:23 ` [PATCH AUTOSEL 4.19 044/244] rtc: 88pm860x: prevent use-after-free on device remove Sasha Levin
2019-05-22 19:23 ` [PATCH AUTOSEL 4.19 045/244] rtc: stm32: manage the get_irq probe defer case Sasha Levin
2019-05-22 19:23 ` [PATCH AUTOSEL 4.19 046/244] scsi: qedi: Abort ep termination if offload not scheduled Sasha Levin
2019-05-22 19:23 ` [PATCH AUTOSEL 4.19 047/244] s390/kexec_file: Fix detection of text segment in ELF loader Sasha Levin
2019-05-22 19:23 ` [PATCH AUTOSEL 4.19 048/244] sched/nohz: Run NOHZ idle load balancer on HK_FLAG_MISC CPUs Sasha Levin
2019-05-22 19:23 ` [PATCH AUTOSEL 4.19 049/244] w1: fix the resume command API Sasha Levin
2019-05-22 19:23 ` [PATCH AUTOSEL 4.19 050/244] s390: qeth: address type mismatch warning Sasha Levin
2019-05-22 19:23 ` [PATCH AUTOSEL 4.19 051/244] dmaengine: pl330: _stop: clear interrupt status Sasha Levin
2019-05-22 19:23 ` [PATCH AUTOSEL 4.19 052/244] mac80211/cfg80211: update bss channel on channel switch Sasha Levin
2019-05-22 19:23 ` [PATCH AUTOSEL 4.19 053/244] USB: serial: fix initial-termios handling Sasha Levin
2019-05-22 19:23 ` [PATCH AUTOSEL 4.19 054/244] libbpf: fix samples/bpf build failure due to undefined UINT32_MAX Sasha Levin
2019-05-22 19:23 ` [PATCH AUTOSEL 4.19 055/244] slimbus: fix a potential NULL pointer dereference in of_qcom_slim_ngd_register Sasha Levin
2019-05-22 19:23 ` [PATCH AUTOSEL 4.19 056/244] driver core: platform: Fix the usage of platform device name(pdev->name) Sasha Levin
2019-05-22 19:23 ` [PATCH AUTOSEL 4.19 057/244] ASoC: fsl_sai: Update is_slave_mode with correct value Sasha Levin
2019-05-22 19:23 ` [PATCH AUTOSEL 4.19 058/244] mwifiex: prevent an array overflow Sasha Levin
2019-05-22 19:23 ` [PATCH AUTOSEL 4.19 059/244] rsi: Fix NULL pointer dereference in kmalloc Sasha Levin
2019-05-22 19:23 ` [PATCH AUTOSEL 4.19 060/244] net: cw1200: fix a NULL pointer dereference Sasha Levin
2019-05-22 19:23 ` [PATCH AUTOSEL 4.19 061/244] at76c50x-usb: Don't register led_trigger if usb_register_driver failed Sasha Levin
2019-05-22 19:23 ` [PATCH AUTOSEL 4.19 062/244] nvme: set 0 capacity if namespace block size exceeds PAGE_SIZE Sasha Levin
2019-05-22 19:23 ` [PATCH AUTOSEL 4.19 063/244] nvme-rdma: fix a NULL deref when an admin connect times out Sasha Levin
2019-05-22 19:23 ` [PATCH AUTOSEL 4.19 064/244] ssb: Fix possible NULL pointer dereference in ssb_host_pcmcia_exit Sasha Levin
2019-05-22 19:23 ` [PATCH AUTOSEL 4.19 065/244] crypto: sun4i-ss - Fix invalid calculation of hash end Sasha Levin
2019-05-22 19:23 ` [PATCH AUTOSEL 4.19 066/244] bcache: avoid potential memleak of list of journal_replay(s) in the CACHE_SYNC branch of run_cache_set Sasha Levin
2019-05-22 19:23 ` [PATCH AUTOSEL 4.19 067/244] bcache: return error immediately in bch_journal_replay() Sasha Levin
2019-05-22 19:23 ` [PATCH AUTOSEL 4.19 068/244] bcache: fix failure in journal relplay Sasha Levin
2019-05-22 19:23 ` [PATCH AUTOSEL 4.19 069/244] bcache: add failure check to run_cache_set() for journal replay Sasha Levin
2019-05-22 19:23 ` [PATCH AUTOSEL 4.19 070/244] bcache: avoid clang -Wunintialized warning Sasha Levin
2019-05-22 19:23 ` [PATCH AUTOSEL 4.19 071/244] RDMA/cma: Consider scope_id while binding to ipv6 ll address Sasha Levin
2019-05-22 19:23 ` [PATCH AUTOSEL 4.19 072/244] vfio-ccw: Do not call flush_workqueue while holding the spinlock Sasha Levin
2019-05-22 19:23 ` [PATCH AUTOSEL 4.19 073/244] vfio-ccw: Release any channel program when releasing/removing vfio-ccw mdev Sasha Levin
2019-05-22 19:23 ` [PATCH AUTOSEL 4.19 074/244] x86/build: Move _etext to actual end of .text Sasha Levin
2019-05-22 19:23 ` [PATCH AUTOSEL 4.19 075/244] smpboot: Place the __percpu annotation correctly Sasha Levin
2019-05-22 19:23 ` [PATCH AUTOSEL 4.19 076/244] x86/mm: Remove in_nmi() warning from 64-bit implementation of vmalloc_fault() Sasha Levin
2019-05-22 19:23 ` [PATCH AUTOSEL 4.19 077/244] mlxsw: spectrum_router: Prevent ipv6 gateway with v4 route via replace and append Sasha Levin
2019-05-22 19:29   ` David Ahern
2019-05-22 19:23 ` [PATCH AUTOSEL 4.19 078/244] mm/uaccess: Use 'unsigned long' to placate UBSAN warnings on older GCC versions Sasha Levin
2019-05-22 19:23 ` [PATCH AUTOSEL 4.19 079/244] Bluetooth: hci_qca: Give enough time to ROME controller to bootup Sasha Levin
2019-05-22 19:23 ` [PATCH AUTOSEL 4.19 080/244] HID: logitech-hidpp: use RAP instead of FAP to get the protocol version Sasha Levin
2019-05-22 19:23 ` [PATCH AUTOSEL 4.19 081/244] pinctrl: pistachio: fix leaked of_node references Sasha Levin
2019-05-22 19:23 ` [PATCH AUTOSEL 4.19 082/244] pinctrl: samsung: " Sasha Levin
2019-05-22 19:23 ` [PATCH AUTOSEL 4.19 083/244] clk: rockchip: undo several noc and special clocks as critical on rk3288 Sasha Levin

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