From patchwork Sun Mar 7 17:34:35 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Paul Cercueil X-Patchwork-Id: 395241 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=-13.8 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI, SPF_HELO_NONE, SPF_PASS 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 B4FD0C433DB for ; Sun, 7 Mar 2021 17:36:08 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 6B53765182 for ; Sun, 7 Mar 2021 17:36:08 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229829AbhCGRf2 (ORCPT ); Sun, 7 Mar 2021 12:35:28 -0500 Received: from aposti.net ([89.234.176.197]:44154 "EHLO aposti.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229783AbhCGRez (ORCPT ); Sun, 7 Mar 2021 12:34:55 -0500 From: Paul Cercueil To: Dmitry Torokhov Cc: od@zcrc.me, linux-input@vger.kernel.org, linux-kernel@vger.kernel.org, Paul Cercueil Subject: [PATCH v2 2/3] input: gpio-keys: Use hrtimer for release timer Date: Sun, 7 Mar 2021 17:34:35 +0000 Message-Id: <20210307173436.78730-2-paul@crapouillou.net> In-Reply-To: <20210307173436.78730-1-paul@crapouillou.net> References: <20210307173436.78730-1-paul@crapouillou.net> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-input@vger.kernel.org Dealing with input, timing is important; if the button should be released in one millisecond, then it should be done in one millisecond and not a hundred milliseconds. Therefore, the standard timer API is not really suitable for this task. Convert the gpio-keys driver to use a hrtimer instead of the standard timer to address this issue. Note that by using a hard IRQ for the hrtimer callback, we can get rid of the spin_lock_irqsave() and spin_unlock_irqrestore(). Signed-off-by: Paul Cercueil --- Notes: v2: No change drivers/input/keyboard/gpio_keys.c | 27 ++++++++++++++++----------- 1 file changed, 16 insertions(+), 11 deletions(-) diff --git a/drivers/input/keyboard/gpio_keys.c b/drivers/input/keyboard/gpio_keys.c index 7fcb2c35c5cc..4b92f49decef 100644 --- a/drivers/input/keyboard/gpio_keys.c +++ b/drivers/input/keyboard/gpio_keys.c @@ -8,6 +8,7 @@ #include +#include #include #include #include @@ -36,7 +37,7 @@ struct gpio_button_data { unsigned short *code; - struct timer_list release_timer; + struct hrtimer release_timer; unsigned int release_delay; /* in msecs, for IRQ-only buttons */ struct delayed_work work; @@ -146,7 +147,7 @@ static void gpio_keys_disable_button(struct gpio_button_data *bdata) if (bdata->gpiod) cancel_delayed_work_sync(&bdata->work); else - del_timer_sync(&bdata->release_timer); + hrtimer_cancel(&bdata->release_timer); bdata->disabled = true; } @@ -415,19 +416,20 @@ static irqreturn_t gpio_keys_gpio_isr(int irq, void *dev_id) return IRQ_HANDLED; } -static void gpio_keys_irq_timer(struct timer_list *t) +static enum hrtimer_restart gpio_keys_irq_timer(struct hrtimer *t) { - struct gpio_button_data *bdata = from_timer(bdata, t, release_timer); + struct gpio_button_data *bdata = container_of(t, + struct gpio_button_data, + release_timer); struct input_dev *input = bdata->input; - unsigned long flags; - spin_lock_irqsave(&bdata->lock, flags); if (bdata->key_pressed) { input_event(input, EV_KEY, *bdata->code, 0); input_sync(input); bdata->key_pressed = false; } - spin_unlock_irqrestore(&bdata->lock, flags); + + return HRTIMER_NORESTART; } static irqreturn_t gpio_keys_irq_isr(int irq, void *dev_id) @@ -457,8 +459,9 @@ static irqreturn_t gpio_keys_irq_isr(int irq, void *dev_id) } if (bdata->release_delay) - mod_timer(&bdata->release_timer, - jiffies + msecs_to_jiffies(bdata->release_delay)); + hrtimer_start(&bdata->release_timer, + ms_to_ktime(bdata->release_delay), + HRTIMER_MODE_REL_HARD); out: spin_unlock_irqrestore(&bdata->lock, flags); return IRQ_HANDLED; @@ -471,7 +474,7 @@ static void gpio_keys_quiesce_key(void *data) if (bdata->gpiod) cancel_delayed_work_sync(&bdata->work); else - del_timer_sync(&bdata->release_timer); + hrtimer_cancel(&bdata->release_timer); } static int gpio_keys_setup_key(struct platform_device *pdev, @@ -595,7 +598,9 @@ static int gpio_keys_setup_key(struct platform_device *pdev, } bdata->release_delay = button->debounce_interval; - timer_setup(&bdata->release_timer, gpio_keys_irq_timer, 0); + hrtimer_init(&bdata->release_timer, + CLOCK_REALTIME, HRTIMER_MODE_REL_HARD); + bdata->release_timer.function = gpio_keys_irq_timer; isr = gpio_keys_irq_isr; irqflags = 0;