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 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id F1A92C0015E for ; Fri, 21 Jul 2023 19:05:47 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231680AbjGUTFq (ORCPT ); Fri, 21 Jul 2023 15:05:46 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:57894 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231679AbjGUTFo (ORCPT ); Fri, 21 Jul 2023 15:05:44 -0400 Received: from dfw.source.kernel.org (dfw.source.kernel.org [139.178.84.217]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 39C0C2D4A for ; Fri, 21 Jul 2023 12:05:42 -0700 (PDT) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits)) (No client certificate requested) by dfw.source.kernel.org (Postfix) with ESMTPS id C896961D90 for ; Fri, 21 Jul 2023 19:05:41 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id D7678C433CD; Fri, 21 Jul 2023 19:05:40 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1689966341; bh=60XPIcNlGnhMKU3gMnOvVNCgEaWji4YYk+vu0/CWXgQ=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=bvtaP4bADNFQV3nVYUF3tTZwNVCqff47/q74y8xzrY3dKFrE4MRX3x+uyH6qirj4D +t7+d5BtbMTdRzeb0WPJfTpk0mM6+W1+z3zC1G5btf3fUJ2/USLQ7Vq9QPlrNRpoWG 2FcSOa0fPZ0SksBnpglzWbztB2Ljz09ohb3i/U+g= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Marek Vasut , Brian Norris , =?UTF-8?q?Uwe=20Kleine-K=C3=B6nig?= , Thierry Reding , Sasha Levin Subject: [PATCH 5.15 309/532] pwm: sysfs: Do not apply state to already disabled PWMs Date: Fri, 21 Jul 2023 18:03:33 +0200 Message-ID: <20230721160631.168005157@linuxfoundation.org> X-Mailer: git-send-email 2.41.0 In-Reply-To: <20230721160614.695323302@linuxfoundation.org> References: <20230721160614.695323302@linuxfoundation.org> User-Agent: quilt/0.67 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org From: Marek Vasut [ Upstream commit 38ba83598633373f47951384cfc389181c8d1bed ] If the PWM is exported but not enabled, do not call pwm_class_apply_state(). First of all, in this case, period may still be unconfigured and this would make pwm_class_apply_state() return -EINVAL, and then suspend would fail. Second, it makes little sense to apply state onto PWM that is not enabled before suspend. Failing case: " $ echo 1 > /sys/class/pwm/pwmchip4/export $ echo mem > /sys/power/state ... pwm pwmchip4: PM: dpm_run_callback(): pwm_class_suspend+0x1/0xa8 returns -22 pwm pwmchip4: PM: failed to suspend: error -22 PM: Some devices failed to suspend, or early wake event detected " Working case: " $ echo 1 > /sys/class/pwm/pwmchip4/export $ echo 100 > /sys/class/pwm/pwmchip4/pwm1/period $ echo 10 > /sys/class/pwm/pwmchip4/pwm1/duty_cycle $ echo mem > /sys/power/state ... " Do not call pwm_class_apply_state() in case the PWM is disabled to fix this issue. Fixes: 7fd4edc57bbae ("pwm: sysfs: Add suspend/resume support") Signed-off-by: Marek Vasut Fixes: ef2bf4997f7d ("pwm: Improve args checking in pwm_apply_state()") Reviewed-by: Brian Norris Reviewed-by: Uwe Kleine-König Signed-off-by: Thierry Reding Signed-off-by: Sasha Levin --- drivers/pwm/sysfs.c | 17 +++++++++++++++++ 1 file changed, 17 insertions(+) diff --git a/drivers/pwm/sysfs.c b/drivers/pwm/sysfs.c index 9903c3a7ecedc..b8417a8d2ef97 100644 --- a/drivers/pwm/sysfs.c +++ b/drivers/pwm/sysfs.c @@ -424,6 +424,13 @@ static int pwm_class_resume_npwm(struct device *parent, unsigned int npwm) if (!export) continue; + /* If pwmchip was not enabled before suspend, do nothing. */ + if (!export->suspend.enabled) { + /* release lock taken in pwm_class_get_state */ + mutex_unlock(&export->lock); + continue; + } + state.enabled = export->suspend.enabled; ret = pwm_class_apply_state(export, pwm, &state); if (ret < 0) @@ -448,7 +455,17 @@ static int __maybe_unused pwm_class_suspend(struct device *parent) if (!export) continue; + /* + * If pwmchip was not enabled before suspend, save + * state for resume time and do nothing else. + */ export->suspend = state; + if (!state.enabled) { + /* release lock taken in pwm_class_get_state */ + mutex_unlock(&export->lock); + continue; + } + state.enabled = false; ret = pwm_class_apply_state(export, pwm, &state); if (ret < 0) { -- 2.39.2