From: Clemens Ladisch Date: Sun, 30 Oct 2005 23:03:34 +0000 (-0800) Subject: [PATCH] hpet: allow shared interrupts X-Git-Tag: v2.6.15-rc1~59^2~15^2~23 X-Git-Url: https://err.no/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=0d29086177aaa1e7d14e6ebb7fc067b3ca6d5c11;p=linux-2.6 [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: Clemens Ladisch Acked-by: Bob Picco Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- diff --git a/drivers/char/hpet.c b/drivers/char/hpet.c index 85d39ff286..8e59639fb0 100644 --- a/drivers/char/hpet.c +++ b/drivers/char/hpet.c @@ -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);