diff options
author | Manfred Schlaegl <manfred.schlaegl@gmx.at> | 2016-05-27 23:36:36 (GMT) |
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committer | Dmitry Torokhov <dmitry.torokhov@gmail.com> | 2016-05-27 23:40:30 (GMT) |
commit | f49cf3b8b4c841457244c461c66186a719e13bcc (patch) | |
tree | 11485c8b7383180ea9a68990dd58e79c5ffd88ab /drivers | |
parent | 6f49a398b266d4895bd7e041db77a2b2ee1482a6 (diff) | |
download | linux-f49cf3b8b4c841457244c461c66186a719e13bcc.tar.xz |
Input: pwm-beeper - fix - scheduling while atomic
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 <manfred.schlaegl@gmx.at>
Cc: stable@vger.kernel.org
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
Diffstat (limited to 'drivers')
-rw-r--r-- | drivers/input/misc/pwm-beeper.c | 69 |
1 files changed, 48 insertions, 21 deletions
diff --git a/drivers/input/misc/pwm-beeper.c b/drivers/input/misc/pwm-beeper.c index f2261ab..18663d4 100644 --- a/drivers/input/misc/pwm-beeper.c +++ b/drivers/input/misc/pwm-beeper.c @@ -20,21 +20,40 @@ #include <linux/platform_device.h> #include <linux/pwm.h> #include <linux/slab.h> +#include <linux/workqueue.h> 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; } |