linux/drivers/input/misc/pcspkr.c
Zoltan Devai 59bdb43769 Input: pcspkr - fix PIT lockup on some chipsets
There've been reports [1] about the sysem bell causing a hard
lockup.  My machine was affected as well: any speaker output hung
the machine completely, nothing in the logs, no magic sysrq,
etc., looked like a hardware problem.  Had a closer look on the
issue, and it turned out that the pcspkr module is responsible.
The cause is the bad setup of Timer 2 in the i8253 controller,
which probably hangs the whole PIT controller.

Intel datasheets [2] state that the timer registers are in an
undefined state after reset and they need to be programmed before
enabling the timer. (And enabling without programming the
frequency first doesn't make sense anyway).

I don't know which chipsets are affected (if not all), it also
depends on the BIOS whether it initializes the timer (e.g. to
beep when you start the machine).

The following patch solved the issue on my ICH6 notebook,
couldn't test it with any others, but should be safe to apply.

[1]
https://bugs.launchpad.net/ubuntu/+source/linux/+bug/146151
https://bugs.launchpad.net/ubuntu/+bug/270790
http://ubuntuforums.org/showthread.php?t=227693
http://bugs.gentoo.org/show_bug.cgi?id=222583
https://bugzilla.redhat.com/show_bug.cgi?id=454225

[2]
http://www.intel.com/assets/pdf/datasheet/252516.pdf
http://www.intel.com/assets/pdf/datasheet/301473.pdf
http://www.intel.com/design/chipsets/datashts/29065503.pdf

Signed-off-by: Zoltan Devai <zdevai@gmail.com>
Signed-off-by: Dmitry Torokhov <dtor@mail.ru>
2008-11-19 16:54:59 -05:00

153 lines
3.3 KiB
C

/*
* PC Speaker beeper driver for Linux
*
* Copyright (c) 2002 Vojtech Pavlik
* Copyright (c) 1992 Orest Zborowski
*
*/
/*
* This program is free software; you can redistribute it and/or modify it
* under the terms of the GNU General Public License version 2 as published by
* the Free Software Foundation
*/
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/init.h>
#include <linux/input.h>
#include <linux/platform_device.h>
#include <asm/io.h>
MODULE_AUTHOR("Vojtech Pavlik <vojtech@ucw.cz>");
MODULE_DESCRIPTION("PC Speaker beeper driver");
MODULE_LICENSE("GPL");
MODULE_ALIAS("platform:pcspkr");
#if defined(CONFIG_MIPS) || defined(CONFIG_X86)
/* Use the global PIT lock ! */
#include <asm/i8253.h>
#else
#include <asm/8253pit.h>
static DEFINE_SPINLOCK(i8253_lock);
#endif
static int pcspkr_event(struct input_dev *dev, unsigned int type, unsigned int code, int value)
{
unsigned int count = 0;
unsigned long flags;
if (type != EV_SND)
return -1;
switch (code) {
case SND_BELL: if (value) value = 1000;
case SND_TONE: break;
default: return -1;
}
if (value > 20 && value < 32767)
count = PIT_TICK_RATE / value;
spin_lock_irqsave(&i8253_lock, flags);
if (count) {
/* set command for counter 2, 2 byte write */
outb_p(0xB6, 0x43);
/* select desired HZ */
outb_p(count & 0xff, 0x42);
outb((count >> 8) & 0xff, 0x42);
/* enable counter 2 */
outb_p(inb_p(0x61) | 3, 0x61);
} else {
/* disable counter 2 */
outb(inb_p(0x61) & 0xFC, 0x61);
}
spin_unlock_irqrestore(&i8253_lock, flags);
return 0;
}
static int __devinit pcspkr_probe(struct platform_device *dev)
{
struct input_dev *pcspkr_dev;
int err;
pcspkr_dev = input_allocate_device();
if (!pcspkr_dev)
return -ENOMEM;
pcspkr_dev->name = "PC Speaker";
pcspkr_dev->phys = "isa0061/input0";
pcspkr_dev->id.bustype = BUS_ISA;
pcspkr_dev->id.vendor = 0x001f;
pcspkr_dev->id.product = 0x0001;
pcspkr_dev->id.version = 0x0100;
pcspkr_dev->dev.parent = &dev->dev;
pcspkr_dev->evbit[0] = BIT_MASK(EV_SND);
pcspkr_dev->sndbit[0] = BIT_MASK(SND_BELL) | BIT_MASK(SND_TONE);
pcspkr_dev->event = pcspkr_event;
err = input_register_device(pcspkr_dev);
if (err) {
input_free_device(pcspkr_dev);
return err;
}
platform_set_drvdata(dev, pcspkr_dev);
return 0;
}
static int __devexit pcspkr_remove(struct platform_device *dev)
{
struct input_dev *pcspkr_dev = platform_get_drvdata(dev);
input_unregister_device(pcspkr_dev);
platform_set_drvdata(dev, NULL);
/* turn off the speaker */
pcspkr_event(NULL, EV_SND, SND_BELL, 0);
return 0;
}
static int pcspkr_suspend(struct platform_device *dev, pm_message_t state)
{
pcspkr_event(NULL, EV_SND, SND_BELL, 0);
return 0;
}
static void pcspkr_shutdown(struct platform_device *dev)
{
/* turn off the speaker */
pcspkr_event(NULL, EV_SND, SND_BELL, 0);
}
static struct platform_driver pcspkr_platform_driver = {
.driver = {
.name = "pcspkr",
.owner = THIS_MODULE,
},
.probe = pcspkr_probe,
.remove = __devexit_p(pcspkr_remove),
.suspend = pcspkr_suspend,
.shutdown = pcspkr_shutdown,
};
static int __init pcspkr_init(void)
{
return platform_driver_register(&pcspkr_platform_driver);
}
static void __exit pcspkr_exit(void)
{
platform_driver_unregister(&pcspkr_platform_driver);
}
module_init(pcspkr_init);
module_exit(pcspkr_exit);