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linux-next/arch/mips/sgi-ip22/ip22-reset.c
Ralf Baechle 7e9e05cad9 MIPS: IP22: Fix hang in power button interrupt handler
The hang was caused by the use of disable_irq() from the interrupt handler
itself.  Fixed by the use of disable_irq_nosync().  The issue was
triggered by:

    commit 3aa551c9b4
    Author: Thomas Gleixner <tglx@linutronix.de>
    Date:   Mon Mar 23 18:28:15 2009 +0100

        genirq: add threaded interrupt handler support

Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2009-05-20 18:53:13 +01:00

208 lines
5.0 KiB
C

/*
* This file is subject to the terms and conditions of the GNU General Public
* License. See the file "COPYING" in the main directory of this archive
* for more details.
*
* Copyright (C) 1997, 1998, 2001, 03, 05, 06 by Ralf Baechle
*/
#include <linux/linkage.h>
#include <linux/init.h>
#include <linux/ds1286.h>
#include <linux/module.h>
#include <linux/interrupt.h>
#include <linux/kernel.h>
#include <linux/sched.h>
#include <linux/notifier.h>
#include <linux/pm.h>
#include <linux/timer.h>
#include <asm/io.h>
#include <asm/irq.h>
#include <asm/system.h>
#include <asm/reboot.h>
#include <asm/sgialib.h>
#include <asm/sgi/ioc.h>
#include <asm/sgi/hpc3.h>
#include <asm/sgi/mc.h>
#include <asm/sgi/ip22.h>
/*
* Just powerdown if init hasn't done after POWERDOWN_TIMEOUT seconds.
* I'm not sure if this feature is a good idea, for now it's here just to
* make the power button make behave just like under IRIX.
*/
#define POWERDOWN_TIMEOUT 120
/*
* Blink frequency during reboot grace period and when panicked.
*/
#define POWERDOWN_FREQ (HZ / 4)
#define PANIC_FREQ (HZ / 8)
static struct timer_list power_timer, blink_timer, debounce_timer;
#define MACHINE_PANICED 1
#define MACHINE_SHUTTING_DOWN 2
static int machine_state;
static void __noreturn sgi_machine_power_off(void)
{
unsigned int tmp;
local_irq_disable();
/* Disable watchdog */
tmp = hpc3c0->rtcregs[RTC_CMD] & 0xff;
hpc3c0->rtcregs[RTC_CMD] = tmp | RTC_WAM;
hpc3c0->rtcregs[RTC_WSEC] = 0;
hpc3c0->rtcregs[RTC_WHSEC] = 0;
while (1) {
sgioc->panel = ~SGIOC_PANEL_POWERON;
/* Good bye cruel world ... */
/* If we're still running, we probably got sent an alarm
interrupt. Read the flag to clear it. */
tmp = hpc3c0->rtcregs[RTC_HOURS_ALARM];
}
}
static void __noreturn sgi_machine_restart(char *command)
{
if (machine_state & MACHINE_SHUTTING_DOWN)
sgi_machine_power_off();
sgimc->cpuctrl0 |= SGIMC_CCTRL0_SYSINIT;
while (1);
}
static void __noreturn sgi_machine_halt(void)
{
if (machine_state & MACHINE_SHUTTING_DOWN)
sgi_machine_power_off();
ArcEnterInteractiveMode();
}
static void power_timeout(unsigned long data)
{
sgi_machine_power_off();
}
static void blink_timeout(unsigned long data)
{
/* XXX fix this for fullhouse */
sgi_ioc_reset ^= (SGIOC_RESET_LC0OFF|SGIOC_RESET_LC1OFF);
sgioc->reset = sgi_ioc_reset;
mod_timer(&blink_timer, jiffies + data);
}
static void debounce(unsigned long data)
{
del_timer(&debounce_timer);
if (sgint->istat1 & SGINT_ISTAT1_PWR) {
/* Interrupt still being sent. */
debounce_timer.expires = jiffies + (HZ / 20); /* 0.05s */
add_timer(&debounce_timer);
sgioc->panel = SGIOC_PANEL_POWERON | SGIOC_PANEL_POWERINTR |
SGIOC_PANEL_VOLDNINTR | SGIOC_PANEL_VOLDNHOLD |
SGIOC_PANEL_VOLUPINTR | SGIOC_PANEL_VOLUPHOLD;
return;
}
if (machine_state & MACHINE_PANICED)
sgimc->cpuctrl0 |= SGIMC_CCTRL0_SYSINIT;
enable_irq(SGI_PANEL_IRQ);
}
static inline void power_button(void)
{
if (machine_state & MACHINE_PANICED)
return;
if ((machine_state & MACHINE_SHUTTING_DOWN) ||
kill_cad_pid(SIGINT, 1)) {
/* No init process or button pressed twice. */
sgi_machine_power_off();
}
machine_state |= MACHINE_SHUTTING_DOWN;
blink_timer.data = POWERDOWN_FREQ;
blink_timeout(POWERDOWN_FREQ);
init_timer(&power_timer);
power_timer.function = power_timeout;
power_timer.expires = jiffies + POWERDOWN_TIMEOUT * HZ;
add_timer(&power_timer);
}
static irqreturn_t panel_int(int irq, void *dev_id)
{
unsigned int buttons;
buttons = sgioc->panel;
sgioc->panel = SGIOC_PANEL_POWERON | SGIOC_PANEL_POWERINTR;
if (sgint->istat1 & SGINT_ISTAT1_PWR) {
/* Wait until interrupt goes away */
disable_irq_nosync(SGI_PANEL_IRQ);
init_timer(&debounce_timer);
debounce_timer.function = debounce;
debounce_timer.expires = jiffies + 5;
add_timer(&debounce_timer);
}
/* Power button was pressed
* ioc.ps page 22: "The Panel Register is called Power Control by Full
* House. Only lowest 2 bits are used. Guiness uses upper four bits
* for volume control". This is not true, all bits are pulled high
* on fullhouse */
if (!(buttons & SGIOC_PANEL_POWERINTR))
power_button();
return IRQ_HANDLED;
}
static int panic_event(struct notifier_block *this, unsigned long event,
void *ptr)
{
if (machine_state & MACHINE_PANICED)
return NOTIFY_DONE;
machine_state |= MACHINE_PANICED;
blink_timer.data = PANIC_FREQ;
blink_timeout(PANIC_FREQ);
return NOTIFY_DONE;
}
static struct notifier_block panic_block = {
.notifier_call = panic_event,
};
static int __init reboot_setup(void)
{
int res;
_machine_restart = sgi_machine_restart;
_machine_halt = sgi_machine_halt;
pm_power_off = sgi_machine_power_off;
res = request_irq(SGI_PANEL_IRQ, panel_int, 0, "Front Panel", NULL);
if (res) {
printk(KERN_ERR "Allocation of front panel IRQ failed\n");
return res;
}
init_timer(&blink_timer);
blink_timer.function = blink_timeout;
atomic_notifier_chain_register(&panic_notifier_list, &panic_block);
return 0;
}
subsys_initcall(reboot_setup);