x86: revert assign IRQs to hpet timer

The commits:

commit 37a47db8d7f0f38dac5acf5a13abbc8f401707fa
Author: Balaji Rao <balajirrao@gmail.com>
Date:   Wed Jan 30 13:30:03 2008 +0100

    x86: assign IRQs to HPET timers, fix

and

commit e3f37a54f690d3e64995ea7ecea08c5ab3070faf
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>

1 files changed, 7 insertions, 44 deletions

diff --git a/drivers/char/hpet.c b/drivers/char/hpet.c
index 465ad35ed38f..1399971be689 100644
--- a/drivers/char/hpet.c
+++ b/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];
+        for (i = 0; i < hdp->hd_nirqs; i++)
+                hpetp->hp_dev[i].hd_hdwirq = hdp->hd_irq[i];
 
-                /* Check if there's already an IRQ assigned to the timer */
-                if (hdp->hd_irq[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",