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Diffstat (limited to 'arch/x86/kernel/i8259.c')
-rw-r--r--arch/x86/kernel/i8259.c29
1 files changed, 21 insertions, 8 deletions
diff --git a/arch/x86/kernel/i8259.c b/arch/x86/kernel/i8259.c
index 16cb827a5b27..be22f5a2192e 100644
--- a/arch/x86/kernel/i8259.c
+++ b/arch/x86/kernel/i8259.c
@@ -295,16 +295,11 @@ static void unmask_8259A(void)
raw_spin_unlock_irqrestore(&i8259A_lock, flags);
}
-static void init_8259A(int auto_eoi)
+static int probe_8259A(void)
{
unsigned long flags;
unsigned char probe_val = ~(1 << PIC_CASCADE_IR);
unsigned char new_val;
-
- i8259A_auto_eoi = auto_eoi;
-
- raw_spin_lock_irqsave(&i8259A_lock, flags);
-
/*
* Check to see if we have a PIC.
* Mask all except the cascade and read
@@ -312,16 +307,28 @@ static void init_8259A(int auto_eoi)
* have a PIC, we will read 0xff as opposed to the
* value we wrote.
*/
+ raw_spin_lock_irqsave(&i8259A_lock, flags);
+
outb(0xff, PIC_SLAVE_IMR); /* mask all of 8259A-2 */
outb(probe_val, PIC_MASTER_IMR);
new_val = inb(PIC_MASTER_IMR);
if (new_val != probe_val) {
printk(KERN_INFO "Using NULL legacy PIC\n");
legacy_pic = &null_legacy_pic;
- raw_spin_unlock_irqrestore(&i8259A_lock, flags);
- return;
}
+ raw_spin_unlock_irqrestore(&i8259A_lock, flags);
+ return nr_legacy_irqs();
+}
+
+static void init_8259A(int auto_eoi)
+{
+ unsigned long flags;
+
+ i8259A_auto_eoi = auto_eoi;
+
+ raw_spin_lock_irqsave(&i8259A_lock, flags);
+
outb(0xff, PIC_MASTER_IMR); /* mask all of 8259A-1 */
/*
@@ -379,6 +386,10 @@ static int legacy_pic_irq_pending_noop(unsigned int irq)
{
return 0;
}
+static int legacy_pic_probe(void)
+{
+ return 0;
+}
struct legacy_pic null_legacy_pic = {
.nr_legacy_irqs = 0,
@@ -388,6 +399,7 @@ struct legacy_pic null_legacy_pic = {
.mask_all = legacy_pic_noop,
.restore_mask = legacy_pic_noop,
.init = legacy_pic_int_noop,
+ .probe = legacy_pic_probe,
.irq_pending = legacy_pic_irq_pending_noop,
.make_irq = legacy_pic_uint_noop,
};
@@ -400,6 +412,7 @@ struct legacy_pic default_legacy_pic = {
.mask_all = mask_8259A,
.restore_mask = unmask_8259A,
.init = init_8259A,
+ .probe = probe_8259A,
.irq_pending = i8259A_irq_pending,
.make_irq = make_8259A_irq,
};