/**
* probe_irq_on - begin an interrupt autodetect
*
* Commence probing for an interrupt. The interrupts are scanned
* and a mask of potential interrupt lines is returned.
*
*/
unsigned long probe_irq_on(void)
{
struct irq_desc *desc;
unsigned long mask = 0;
unsigned int status;
int i;
/*
* quiesce the kernel, or at least the asynchronous portion
*/
async_synchronize_full();
mutex_lock(&probing_active);
/*
* something may have generated an irq long ago and we want to
* flush such a longstanding irq before considering it as spurious.
*/
for_each_irq_desc_reverse(i, desc) {
atomic_spin_lock_irq(&desc->lock);
if (!desc->action && !(desc->status & IRQ_NOPROBE)) {
/*
* An old-style architecture might still have
* the handle_bad_irq handler there:
*/
compat_irq_chip_set_default_handler(desc);
/*
* Some chips need to know about probing in
* progress:
*/
if (desc->chip->set_type)
desc->chip->set_type(i, IRQ_TYPE_PROBE);
desc->chip->startup(i);
}
atomic_spin_unlock_irq(&desc->lock);
}
unsigned long probe_irq_on(void)
{
struct irq_desc *desc;
unsigned long mask = 0;
unsigned int status;
int i;
async_synchronize_full();
mutex_lock(&probing_active);
for_each_irq_desc_reverse(i, desc) {
spin_lock_irq(&desc->lock);
if (!desc->action && !(desc->status & IRQ_NOPROBE)) {
compat_irq_chip_set_default_handler(desc);
if (desc->chip->set_type)
desc->chip->set_type(i, IRQ_TYPE_PROBE);
desc->chip->startup(i);
}
spin_unlock_irq(&desc->lock);
}
/**
* probe_irq_on - begin an interrupt autodetect
*
* Commence probing for an interrupt. The interrupts are scanned
* and a mask of potential interrupt lines is returned.
*
*/
unsigned long probe_irq_on(void)
{
struct irq_desc *desc;
unsigned long mask;
unsigned int i;
mutex_lock(&probing_active);
/*
* something may have generated an irq long ago and we want to
* flush such a longstanding irq before considering it as spurious.
*/
for (i = NR_IRQS-1; i > 0; i--) {
desc = irq_desc + i;
spin_lock_irq(&desc->lock);
if (!desc->action && !(desc->status & IRQ_NOPROBE)) {
/*
* An old-style architecture might still have
* the handle_bad_irq handler there:
*/
compat_irq_chip_set_default_handler(desc);
/*
* Some chips need to know about probing in
* progress:
*/
if (desc->chip->set_type)
desc->chip->set_type(i, IRQ_TYPE_PROBE);
desc->chip->startup(i);
}
spin_unlock_irq(&desc->lock);
}
/* Wait for longstanding interrupts to trigger. */
msleep(20);
/*
* enable any unassigned irqs
* (we must startup again here because if a longstanding irq
* happened in the previous stage, it may have masked itself)
*/
for (i = NR_IRQS-1; i > 0; i--) {
desc = irq_desc + i;
spin_lock_irq(&desc->lock);
if (!desc->action && !(desc->status & IRQ_NOPROBE)) {
desc->status |= IRQ_AUTODETECT | IRQ_WAITING;
if (desc->chip->startup(i))
desc->status |= IRQ_PENDING;
}
spin_unlock_irq(&desc->lock);
}
/*
* Wait for spurious interrupts to trigger
*/
msleep(100);
/*
* Now filter out any obviously spurious interrupts
*/
mask = 0;
for (i = 0; i < NR_IRQS; i++) {
unsigned int status;
desc = irq_desc + i;
spin_lock_irq(&desc->lock);
status = desc->status;
if (status & IRQ_AUTODETECT) {
/* It triggered already - consider it spurious. */
if (!(status & IRQ_WAITING)) {
desc->status = status & ~IRQ_AUTODETECT;
desc->chip->shutdown(i);
} else
if (i < 32)
mask |= 1 << i;
}
spin_unlock_irq(&desc->lock);
}
return mask;
}
