From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-8.5 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS, URIBL_BLOCKED,USER_AGENT_MUTT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 70FDAC282E1 for ; Sun, 26 May 2019 07:39:00 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 455822081C for ; Sun, 26 May 2019 07:39:00 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727607AbfEZHi7 (ORCPT ); Sun, 26 May 2019 03:38:59 -0400 Received: from atrey.karlin.mff.cuni.cz ([195.113.26.193]:39748 "EHLO atrey.karlin.mff.cuni.cz" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725972AbfEZHi6 (ORCPT ); Sun, 26 May 2019 03:38:58 -0400 Received: by atrey.karlin.mff.cuni.cz (Postfix, from userid 512) id 9F39A802CD; Sun, 26 May 2019 09:38:45 +0200 (CEST) Date: Sun, 26 May 2019 09:38:55 +0200 From: Pavel Machek To: hughd@google.com, jacek.anaszewski@gmail.com, linux-leds@vger.kernel.org, kernel list Subject: leds: avoid flush_work in atomic context Message-ID: <20190526073854.GA13681@amd> MIME-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha1; protocol="application/pgp-signature"; boundary="UlVJffcvxoiEqYs2" Content-Disposition: inline User-Agent: Mutt/1.5.23 (2014-03-12) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org --UlVJffcvxoiEqYs2 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Content-Transfer-Encoding: quoted-printable 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. =20 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 =20 Fixes: 0db37915d912 Signed-off-by: Pavel Machek Tested-by: Hugh Dickins =20 diff --git a/drivers/leds/led-core.c b/drivers/leds/led-core.c index aefac4d..9f8da39 100644 --- a/drivers/leds/led-core.c +++ b/drivers/leds/led-core.c @@ -166,11 +166,6 @@ static void led_blink_setup(struct led_classdev *led_c= dev, 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/le= dtrig-timer.c index ca898c1..427fc3c 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 *le= d_cdev) led_cdev->flags &=3D ~LED_INIT_DEFAULT_TRIGGER; } =20 + /* + * 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); =20 --=20 (english) http://www.livejournal.com/~pavelmachek (cesky, pictures) http://atrey.karlin.mff.cuni.cz/~pavel/picture/horses/blo= g.html --UlVJffcvxoiEqYs2 Content-Type: application/pgp-signature; name="signature.asc" Content-Description: Digital signature -----BEGIN PGP SIGNATURE----- Version: GnuPG v1 iEYEARECAAYFAlzqQo4ACgkQMOfwapXb+vJZ5wCeOuzhonhKAc9kR3QYlQgTrzhT nkwAoIcNo6zD0gpTKkeUuttcHes4o9OP =vzsX -----END PGP SIGNATURE----- --UlVJffcvxoiEqYs2--