x86: revert assign IRQs to hpet timer

The commits:

commit 37a47db8d7
Author: Balaji Rao <balajirrao@gmail.com>
Date:   Wed Jan 30 13:30:03 2008 +0100

    x86: assign IRQs to HPET timers, fix

and

commit e3f37a54f6
Author: Balaji Rao <balajirrao@gmail.com>
Date:   Wed Jan 30 13:30:03 2008 +0100

    x86: assign IRQs to HPET timers

have been identified to cause a regression on some platforms due to
the assignement of legacy IRQs which makes the legacy devices
connected to those IRQs disfunctional.

Revert them.

This fixes http://bugzilla.kernel.org/show_bug.cgi?id=10382

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

arch/x86/kernel/hpet.c

@@ -133,13 +133,16 @@ static void hpet_reserve_platform_timers(unsigned long id)
 #ifdef CONFIG_HPET_EMULATE_RTC
 	hpet_reserve_timer(&hd, 1);
 #endif
+
 	hd.hd_irq[0] = HPET_LEGACY_8254;
 	hd.hd_irq[1] = HPET_LEGACY_RTC;
 
 	for (i = 2; i < nrtimers; timer++, i++)
 		hd.hd_irq[i] = (timer->hpet_config & Tn_INT_ROUTE_CNF_MASK) >>
 			Tn_INT_ROUTE_CNF_SHIFT;
+
 	hpet_alloc(&hd);
+
 }
 #else
 static void hpet_reserve_platform_timers(unsigned long id) { }

drivers/char/hpet.c

@@ -731,14 +731,14 @@ static unsigned long hpet_calibrate(struct hpets *hpetp)
 
 int hpet_alloc(struct hpet_data *hdp)
 {
-	u64 cap, mcfg, hpet_config;
+	u64 cap, mcfg;
 	struct hpet_dev *devp;
-	u32 i, ntimer, irq;
+	u32 i, ntimer;
 	struct hpets *hpetp;
 	size_t siz;
 	struct hpet __iomem *hpet;
 	static struct hpets *last = NULL;
-	unsigned long period, irq_bitmap;
+	unsigned long period;
 	unsigned long long temp;
 
 	/*
@@ -765,47 +765,11 @@ int hpet_alloc(struct hpet_data *hdp)
 	hpetp->hp_hpet_phys = hdp->hd_phys_address;
 
 	hpetp->hp_ntimer = hdp->hd_nirqs;
-	hpet = hpetp->hp_hpet;
 
-	/* Assign IRQs statically for legacy devices */
-	hpetp->hp_dev[0].hd_hdwirq = hdp->hd_irq[0];
-	hpetp->hp_dev[1].hd_hdwirq = hdp->hd_irq[1];
-
-	/* Assign IRQs dynamically for the others */
-	for (i = 2, devp = &hpetp->hp_dev[2]; i < hdp->hd_nirqs; i++, devp++) {
-		struct hpet_timer __iomem *timer;
-
-		timer = &hpet->hpet_timers[devp - hpetp->hp_dev];
-
-		/* Check if there's already an IRQ assigned to the timer */
-		if (hdp->hd_irq[i]) {
+	for (i = 0; i < hdp->hd_nirqs; i++)
 		hpetp->hp_dev[i].hd_hdwirq = hdp->hd_irq[i];
-			continue;
-		}
 
-		hpet_config = readq(&timer->hpet_config);
-		irq_bitmap = (hpet_config & Tn_INT_ROUTE_CAP_MASK)
-			>> Tn_INT_ROUTE_CAP_SHIFT;
-		if (!irq_bitmap)
-			irq = 0;        /* No valid IRQ Assignable */
-		else {
-			irq = find_first_bit(&irq_bitmap, 32);
-			do {
-				hpet_config |= irq << Tn_INT_ROUTE_CNF_SHIFT;
-				writeq(hpet_config, &timer->hpet_config);
-
-				/*
-				 * Verify whether we have written a valid
-				 * IRQ number by reading it back again
-				 */
-				hpet_config = readq(&timer->hpet_config);
-				if (irq == (hpet_config & Tn_INT_ROUTE_CNF_MASK)
-						>> Tn_INT_ROUTE_CNF_SHIFT)
-					break;  /* Success */
-			} while ((irq = (find_next_bit(&irq_bitmap, 32, irq))));
-		}
-		hpetp->hp_dev[i].hd_hdwirq = irq;
-	}
+	hpet = hpetp->hp_hpet;
 
 	cap = readq(&hpet->hpet_cap);
 
@@ -836,8 +800,7 @@ int hpet_alloc(struct hpet_data *hdp)
 		hpetp->hp_which, hdp->hd_phys_address,
 		hpetp->hp_ntimer > 1 ? "s" : "");
 	for (i = 0; i < hpetp->hp_ntimer; i++)
-		printk("%s %d", i > 0 ? "," : "",
-				hpetp->hp_dev[i].hd_hdwirq);
+		printk("%s %d", i > 0 ? "," : "", hdp->hd_irq[i]);
 	printk("\n");
 
 	printk(KERN_INFO "hpet%u: %u %d-bit timers, %Lu Hz\n",

include/linux/hpet.h

@@ -64,7 +64,7 @@ struct hpet {
  */
 
 #define	Tn_INT_ROUTE_CAP_MASK		(0xffffffff00000000ULL)
-#define	Tn_INT_ROUTE_CAP_SHIFT		(32UL)
+#define	Tn_INI_ROUTE_CAP_SHIFT		(32UL)
 #define	Tn_FSB_INT_DELCAP_MASK		(0x8000UL)
 #define	Tn_FSB_INT_DELCAP_SHIFT		(15)
 #define	Tn_FSB_EN_CNF_MASK		(0x4000UL)