From patchwork Wed May 26 18:00:20 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: =?utf-8?q?Marek_Beh=C3=BAn?= X-Patchwork-Id: 12282503 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=-19.4 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,USER_AGENT_GIT autolearn=unavailable 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 BF2B3C47089 for ; Wed, 26 May 2021 18:01:48 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id A45186113D for ; Wed, 26 May 2021 18:01:46 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S235272AbhEZSDR (ORCPT ); Wed, 26 May 2021 14:03:17 -0400 Received: from mail.kernel.org ([198.145.29.99]:58710 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S235414AbhEZSDN (ORCPT ); Wed, 26 May 2021 14:03:13 -0400 Received: by mail.kernel.org (Postfix) with ESMTPSA id 14805613C5; Wed, 26 May 2021 18:01:39 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1622052101; bh=YYukrN0gtN9kwTFXmThy4546a/7oLlBsJI81+BNz9/8=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=a//HXFXo35dDN1h8bbn/ar2X9NNjvm/24NE5UPYchG0HWzw9+YWZj6SaV4uaZ4Jon NCQzTDNprsUKr2zzxylukjk7WCGJyVL2VxU7AG2u2G0UV9apaQPU/xz8kmCicLTlYk UW2GvcQQU46HEYhu7k1scQTuz2fJFgD53w4jgDMcC8PjshqXEbunwsUcsx3q8aOp4o ltfYEDoFrp+hUER9eHiqEThvx+Q/p2YyLndbd0qrc+n1iToMI82AEZiCTtDt5tE3w5 byRVih5+yR+jhbFkaVv3/QurVkGZlUe1KXn2/1IoYiEqlj97myVVh+Pog54aH4Rm21 uH6ujIU9ry19g== From: =?utf-8?q?Marek_Beh=C3=BAn?= To: linux-leds@vger.kernel.org Cc: netdev@vger.kernel.org, Pavel Machek , Dan Murphy , Russell King , Andrew Lunn , Matthias Schiffer , Jacek Anaszewski , Mauro Carvalho Chehab , =?utf-8?q?Marek_Beh?= =?utf-8?q?=C3=BAn?= Subject: [PATCH leds v1 5/5] leds: trigger: netdev: change spinlock to mutex Date: Wed, 26 May 2021 20:00:20 +0200 Message-Id: <20210526180020.13557-6-kabel@kernel.org> X-Mailer: git-send-email 2.26.3 In-Reply-To: <20210526180020.13557-1-kabel@kernel.org> References: <20210526180020.13557-1-kabel@kernel.org> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org Using spinlocks requires that the trigger_offload() method cannot sleep. This can be problematic for some hardware, since access to registers may sleep. We can change the spinlock to mutex because, according to Jacek: register_netdevice_notifier() registers raw notifier chain, whose callbacks are not called from atomic context and there are no restrictions on callbacks. See include/linux/notifier.h. Signed-off-by: Marek Behún --- drivers/leds/trigger/ledtrig-netdev.c | 14 +++++++------- include/linux/ledtrig.h | 4 ++-- 2 files changed, 9 insertions(+), 9 deletions(-) diff --git a/drivers/leds/trigger/ledtrig-netdev.c b/drivers/leds/trigger/ledtrig-netdev.c index b6d51b24c213..7073cc6b8ca2 100644 --- a/drivers/leds/trigger/ledtrig-netdev.c +++ b/drivers/leds/trigger/ledtrig-netdev.c @@ -79,9 +79,9 @@ static ssize_t device_name_show(struct device *dev, struct led_netdev_data *trigger_data = led_trigger_get_drvdata(dev); ssize_t len; - spin_lock_bh(&trigger_data->lock); + mutex_lock(&trigger_data->lock); len = sprintf(buf, "%s\n", trigger_data->device_name); - spin_unlock_bh(&trigger_data->lock); + mutex_unlock(&trigger_data->lock); return len; } @@ -97,7 +97,7 @@ static ssize_t device_name_store(struct device *dev, cancel_delayed_work_sync(&trigger_data->work); - spin_lock_bh(&trigger_data->lock); + mutex_lock(&trigger_data->lock); if (trigger_data->net_dev) { dev_put(trigger_data->net_dev); @@ -121,7 +121,7 @@ static ssize_t device_name_store(struct device *dev, trigger_data->last_activity = 0; set_baseline_state(trigger_data); - spin_unlock_bh(&trigger_data->lock); + mutex_unlock(&trigger_data->lock); return size; } @@ -295,7 +295,7 @@ static int netdev_trig_notify(struct notifier_block *nb, cancel_delayed_work_sync(&trigger_data->work); - spin_lock_bh(&trigger_data->lock); + mutex_lock(&trigger_data->lock); clear_bit(NETDEV_LED_MODE_LINKUP, &trigger_data->mode); switch (evt) { @@ -319,7 +319,7 @@ static int netdev_trig_notify(struct notifier_block *nb, set_baseline_state(trigger_data); - spin_unlock_bh(&trigger_data->lock); + mutex_unlock(&trigger_data->lock); return NOTIFY_DONE; } @@ -380,7 +380,7 @@ static int netdev_trig_activate(struct led_classdev *led_cdev) if (!trigger_data) return -ENOMEM; - spin_lock_init(&trigger_data->lock); + mutex_init(&trigger_data->lock); trigger_data->notifier.notifier_call = netdev_trig_notify; trigger_data->notifier.priority = 10; diff --git a/include/linux/ledtrig.h b/include/linux/ledtrig.h index a6a813bb154a..bd8cdcfaf232 100644 --- a/include/linux/ledtrig.h +++ b/include/linux/ledtrig.h @@ -8,13 +8,13 @@ #include #include +#include #include -#include #if IS_ENABLED(CONFIG_LEDS_TRIGGER_NETDEV) struct led_netdev_data { - spinlock_t lock; + struct mutex lock; struct delayed_work work; struct notifier_block notifier;