Commit 0d290861 authored by Clemens Ladisch's avatar Clemens Ladisch Committed by Linus Torvalds
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[PATCH] hpet: allow shared interrupts 



This patch adds support for shared HPET interrupts.

The driver previously acknowledged interrupts for both edge and level
interrupts, but didn't actually allow a shared interrupt in the latter case.

We use a new per-timer flag to save whether the timer's interrupt might be
shared, and use it to do the processing required for level interrupts only if
necessary.

Signed-off-by: default avatarClemens Ladisch <clemens@ladisch.de>
Acked-by: default avatarBob Picco <bob.picco@hp.com>
Signed-off-by: default avatarAndrew Morton <akpm@osdl.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@osdl.org>
parent 189e2dd1

drivers/char/hpet.c

+21 −7
Original line number Diff line number Diff line
@@ -90,6 +90,7 @@ static struct hpets *hpets; 
#define	HPET_OPEN		0x0001

#define	HPET_IE			0x0002	/* interrupt enabled */

#define	HPET_PERIODIC		0x0004

#define	HPET_SHARED_IRQ		0x0008



#if BITS_PER_LONG == 64

#define	write_counter(V, MC)	writeq(V, MC)
@@ -120,6 +121,11 @@ static irqreturn_t hpet_interrupt(int irq, void *data, struct pt_regs *regs) 
	unsigned long isr;



	devp = data;

	isr = 1 << (devp - devp->hd_hpets->hp_dev);



	if ((devp->hd_flags & HPET_SHARED_IRQ) &&

	    !(isr & readl(&devp->hd_hpet->hpet_isr)))

		return IRQ_NONE;



	spin_lock(&hpet_lock);

	devp->hd_irqdata++;
@@ -137,8 +143,8 @@ static irqreturn_t hpet_interrupt(int irq, void *data, struct pt_regs *regs) 
			      &devp->hd_timer->hpet_compare);

	}



	isr = (1 << (devp - devp->hd_hpets->hp_dev));

	writeq(isr, &devp->hd_hpet->hpet_isr);

	if (devp->hd_flags & HPET_SHARED_IRQ)

		writel(isr, &devp->hd_hpet->hpet_isr);

	spin_unlock(&hpet_lock);



	spin_lock(&hpet_task_lock);
@@ -375,15 +381,21 @@ static int hpet_ioctl_ieon(struct hpet_dev *devp) 
	}



	devp->hd_flags |= HPET_IE;



	if (readl(&timer->hpet_config) & Tn_INT_TYPE_CNF_MASK)

		devp->hd_flags |= HPET_SHARED_IRQ;

	spin_unlock_irq(&hpet_lock);



	irq = devp->hd_hdwirq;



	if (irq) {

		sprintf(devp->hd_name, "hpet%d", (int)(devp - hpetp->hp_dev));

		unsigned long irq_flags;



		if (request_irq

		    (irq, hpet_interrupt, SA_INTERRUPT, devp->hd_name, (void *)devp)) {

		sprintf(devp->hd_name, "hpet%d", (int)(devp - hpetp->hp_dev));

		irq_flags = devp->hd_flags & HPET_SHARED_IRQ

						? SA_SHIRQ : SA_INTERRUPT;

		if (request_irq(irq, hpet_interrupt, irq_flags,

				devp->hd_name, (void *)devp)) {

			printk(KERN_ERR "hpet: IRQ %d is not free\n", irq);

			irq = 0;

		}
@@ -417,8 +429,10 @@ static int hpet_ioctl_ieon(struct hpet_dev *devp) 
		write_counter(t + m + hpetp->hp_delta, &timer->hpet_compare);

	}



	isr = (1 << (devp - hpets->hp_dev));

	writeq(isr, &hpet->hpet_isr);

	if (devp->hd_flags & HPET_SHARED_IRQ) {

		isr = 1 << (devp - hpets->hp_dev);

		writel(isr, &hpet->hpet_isr);

	}

	writeq(g, &timer->hpet_config);

	local_irq_restore(flags);

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