From patchwork Tue Jun 1 00:51:50 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: 451630 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=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 658A6C47083 for ; Tue, 1 Jun 2021 00:52:17 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 4AF4161377 for ; Tue, 1 Jun 2021 00:52:17 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232490AbhFAAxz (ORCPT ); Mon, 31 May 2021 20:53:55 -0400 Received: from mail.kernel.org ([198.145.29.99]:46090 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232517AbhFAAxv (ORCPT ); Mon, 31 May 2021 20:53:51 -0400 Received: by mail.kernel.org (Postfix) with ESMTPSA id EC7AC613AD; Tue, 1 Jun 2021 00:52:08 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1622508730; bh=Nu/uf/ccww5gMoSX6cDd3d8bysChi7qjNX8MVEc2FMw=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=eCUd4yCuYC+w4CZx7hXJJ40s3wA3Fu4IqnCQ5K+MlU+Abnpbs+Kl0XJWyWEi7di7b dImId6l4WTdkcnnLlQ0nzlFFb3nXCs3bQtCEytv+pEeaObt+ovQjW9n1S4E5+l5rQR lpEVnGvusmY85GTI4kSymLzWO0WNpuMv9uoV+bCxxlQDGKLnwj/bM0odvbImVvyoCu 78RsWCx9k5CPqdWpU36y7HQN9QzLXlC7KrrK54gpaRZ+XF20R33COWjJoOtkBuRh8H dmT5CbIci4QWP4kH22VrKjZf6rTwLTdgSEijaYH8pzwb6JV4Hxs8kBnos9z4V6xHGt 77iG83CjR6LlQ== 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=C3=BAn?= Subject: [PATCH leds v2 05/10] leds: trigger: netdev: change spinlock to mutex Date: Tue, 1 Jun 2021 02:51:50 +0200 Message-Id: <20210601005155.27997-6-kabel@kernel.org> X-Mailer: git-send-email 2.26.3 In-Reply-To: <20210601005155.27997-1-kabel@kernel.org> References: <20210601005155.27997-1-kabel@kernel.org> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-leds@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-netdev.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 1f1b63d5a78d..341e1f174c5b 100644 --- a/drivers/leds/trigger/ledtrig-netdev.c +++ b/drivers/leds/trigger/ledtrig-netdev.c @@ -83,9 +83,9 @@ 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; } @@ -101,7 +101,7 @@ 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); @@ -125,7 +125,7 @@ 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; } @@ -299,7 +299,7 @@ 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) { @@ -323,7 +323,7 @@ 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; } @@ -384,7 +384,7 @@ 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-netdev.h b/include/linux/ledtrig-netdev.h index d6be039e1247..b93687ecc801 100644 --- a/include/linux/ledtrig-netdev.h +++ b/include/linux/ledtrig-netdev.h @@ -8,11 +8,11 @@ #include #include +#include #include -#include struct led_netdev_data { - spinlock_t lock; + struct mutex lock; struct delayed_work work; struct notifier_block notifier;