Threaded irq handler question
From: Will Newton
Date: Wed Apr 21 2010 - 12:35:40 EST
Hi all,
I have a threaded irq handler attached to a level-triggered gpio
interrupt line. The check handler checks the status of the gpio line
and disables the irq line amd returns WAKE_THREAD in that case:
static irqreturn_t isr_check(int irq, void *p)
{
if (gpio_status()) {
disable_irq_nosync(irq);
return IRQ_WAKE_THREAD;
}
return IRQ_NONE;
}
The thread then does some i2c transactions that will eventually
deassert the gpio line:
static irqreturn_t isr(int irq, void *p)
{
/* do some i2c transfers */
enable_irq(irq);
return IRQ_HANDLED;
}
My problem is that this structure does not work, because once I call
disable_irq_nosync() on the irq in the check handler the thread will
no longer run because the irq is disabled. However if I don't call
disable_irq_nosync() I will get endless irqs because the line is
level-triggered and will not be deasserted until the thread has run.
Could someone tell me what I'm doing wrong here?
Thanks,
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