From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932368AbcFIVhr (ORCPT ); Thu, 9 Jun 2016 17:37:47 -0400 Received: from youngberry.canonical.com ([91.189.89.112]:51339 "EHLO youngberry.canonical.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753364AbcFIVTu (ORCPT ); Thu, 9 Jun 2016 17:19:50 -0400 From: Kamal Mostafa To: linux-kernel@vger.kernel.org, stable@vger.kernel.org, kernel-team@lists.ubuntu.com Cc: Manfred Schlaegl , Dmitry Torokhov , Kamal Mostafa Subject: [PATCH 4.2.y-ckt 144/206] Input: pwm-beeper - fix - scheduling while atomic Date: Thu, 9 Jun 2016 14:15:53 -0700 Message-Id: <1465507015-23052-145-git-send-email-kamal@canonical.com> X-Mailer: git-send-email 2.7.4 In-Reply-To: <1465507015-23052-1-git-send-email-kamal@canonical.com> References: <1465507015-23052-1-git-send-email-kamal@canonical.com> X-Extended-Stable: 4.2 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 4.2.8-ckt12 -stable review patch. If anyone has any objections, please let me know. ---8<------------------------------------------------------------ From: Manfred Schlaegl commit f49cf3b8b4c841457244c461c66186a719e13bcc upstream. Pwm config may sleep so defer it using a worker. On a Freescale i.MX53 based board we ran into "BUG: scheduling while atomic" because input_inject_event locks interrupts, but imx_pwm_config_v2 sleeps. Tested on Freescale i.MX53 SoC with 4.6.0. Signed-off-by: Manfred Schlaegl Signed-off-by: Dmitry Torokhov Signed-off-by: Kamal Mostafa --- drivers/input/misc/pwm-beeper.c | 69 ++++++++++++++++++++++++++++------------- 1 file changed, 48 insertions(+), 21 deletions(-) diff --git a/drivers/input/misc/pwm-beeper.c b/drivers/input/misc/pwm-beeper.c index e82edf8..9021725 100644 --- a/drivers/input/misc/pwm-beeper.c +++ b/drivers/input/misc/pwm-beeper.c @@ -20,21 +20,40 @@ #include #include #include +#include struct pwm_beeper { struct input_dev *input; struct pwm_device *pwm; + struct work_struct work; unsigned long period; }; #define HZ_TO_NANOSECONDS(x) (1000000000UL/(x)) +static void __pwm_beeper_set(struct pwm_beeper *beeper) +{ + unsigned long period = beeper->period; + + if (period) { + pwm_config(beeper->pwm, period / 2, period); + pwm_enable(beeper->pwm); + } else + pwm_disable(beeper->pwm); +} + +static void pwm_beeper_work(struct work_struct *work) +{ + struct pwm_beeper *beeper = + container_of(work, struct pwm_beeper, work); + + __pwm_beeper_set(beeper); +} + static int pwm_beeper_event(struct input_dev *input, unsigned int type, unsigned int code, int value) { - int ret = 0; struct pwm_beeper *beeper = input_get_drvdata(input); - unsigned long period; if (type != EV_SND || value < 0) return -EINVAL; @@ -49,22 +68,31 @@ static int pwm_beeper_event(struct input_dev *input, return -EINVAL; } - if (value == 0) { - pwm_disable(beeper->pwm); - } else { - period = HZ_TO_NANOSECONDS(value); - ret = pwm_config(beeper->pwm, period / 2, period); - if (ret) - return ret; - ret = pwm_enable(beeper->pwm); - if (ret) - return ret; - beeper->period = period; - } + if (value == 0) + beeper->period = 0; + else + beeper->period = HZ_TO_NANOSECONDS(value); + + schedule_work(&beeper->work); return 0; } +static void pwm_beeper_stop(struct pwm_beeper *beeper) +{ + cancel_work_sync(&beeper->work); + + if (beeper->period) + pwm_disable(beeper->pwm); +} + +static void pwm_beeper_close(struct input_dev *input) +{ + struct pwm_beeper *beeper = input_get_drvdata(input); + + pwm_beeper_stop(beeper); +} + static int pwm_beeper_probe(struct platform_device *pdev) { unsigned long pwm_id = (unsigned long)dev_get_platdata(&pdev->dev); @@ -87,6 +115,8 @@ static int pwm_beeper_probe(struct platform_device *pdev) goto err_free; } + INIT_WORK(&beeper->work, pwm_beeper_work); + beeper->input = input_allocate_device(); if (!beeper->input) { dev_err(&pdev->dev, "Failed to allocate input device\n"); @@ -106,6 +136,7 @@ static int pwm_beeper_probe(struct platform_device *pdev) beeper->input->sndbit[0] = BIT(SND_TONE) | BIT(SND_BELL); beeper->input->event = pwm_beeper_event; + beeper->input->close = pwm_beeper_close; input_set_drvdata(beeper->input, beeper); @@ -135,7 +166,6 @@ static int pwm_beeper_remove(struct platform_device *pdev) input_unregister_device(beeper->input); - pwm_disable(beeper->pwm); pwm_free(beeper->pwm); kfree(beeper); @@ -147,8 +177,7 @@ static int __maybe_unused pwm_beeper_suspend(struct device *dev) { struct pwm_beeper *beeper = dev_get_drvdata(dev); - if (beeper->period) - pwm_disable(beeper->pwm); + pwm_beeper_stop(beeper); return 0; } @@ -157,10 +186,8 @@ static int __maybe_unused pwm_beeper_resume(struct device *dev) { struct pwm_beeper *beeper = dev_get_drvdata(dev); - if (beeper->period) { - pwm_config(beeper->pwm, beeper->period / 2, beeper->period); - pwm_enable(beeper->pwm); - } + if (beeper->period) + __pwm_beeper_set(beeper); return 0; } -- 2.7.4