[PATCH x86] i8259A_32: Remove redundant irq_desc[NR_IRQ] initialization

[PATCH x86] i8259A_32: Remove redundant irq_desc[NR_IRQ] initialization

[Ahmed S. Darwish]

Hi all,

Remove redundant irq_desc[NR_IRQS] element initialization in 
init_ISA_irqs(). irq_desc[NR_IRQS] is already statically 
initialized with the same values in kernel/irq/handle.c .

Signed-off-by: Ahmed S. Darwish <darwish.07@gmail.com>
---

 i8259_32.c |   26 ++++++--------------------
 1 file changed, 6 insertions(+), 20 deletions(-)

Tested only on a UP machine with an i8259A PIC.

diff --git a/arch/x86/kernel/i8259_32.c b/arch/x86/kernel/i8259_32.c
index 2d25b77..0fea87d 100644
--- a/arch/x86/kernel/i8259_32.c
+++ b/arch/x86/kernel/i8259_32.c
@@ -26,8 +26,6 @@
  * present in the majority of PC/AT boxes.
  * plus some generic x86 specific things if generic specifics makes
  * any sense at all.
- * this file should become arch/i386/kernel/irq.c when the old irq.c
- * moves to arch independent land
  */
 
 static int i8259A_auto_eoi;
@@ -362,24 +360,12 @@ void __init init_ISA_irqs (void)
 #endif
 	init_8259A(0);
 
-	for (i = 0; i < NR_IRQS; i++) {
-		irq_desc[i].status = IRQ_DISABLED;
-		irq_desc[i].action = NULL;
-		irq_desc[i].depth = 1;
-
-		if (i < 16) {
-			/*
-			 * 16 old-style INTA-cycle interrupts:
-			 */
-			set_irq_chip_and_handler_name(i, &i8259A_chip,
-						      handle_level_irq, "XT");
-		} else {
-			/*
-			 * 'high' PCI IRQs filled in on demand
-			 */
-			irq_desc[i].chip = &no_irq_chip;
-		}
-	}
+	/*
+	 * 16 old-style INTA-cycle interrupts:
+	 */
+	for (i = 0; i < 16; i++)
+		set_irq_chip_and_handler_name(i, &i8259A_chip,
+					      handle_level_irq, "XT");
 }
 
 /* Overridden in paravirt.c */

Regards,

-- 
Ahmed S. Darwish
Homepage: http://darwish.07.googlepages.com
Blog: http://darwish-07.blogspot.com

Re: [PATCH x86] i8259A_32: Remove redundant irq_desc[NR_IRQ] initialization

[Ingo Molnar]

* Ahmed S. Darwish <darwish.07@gmail.com> wrote:

> Remove redundant irq_desc[NR_IRQS] element initialization in 
> init_ISA_irqs(). irq_desc[NR_IRQS] is already statically initialized 
> with the same values in kernel/irq/handle.c .

nice catch - applied. This also saves a few bytes of image space:

   text    data     bss     dec     hex filename
   1389     356      14    1759     6df i8259_32.o.before
   1325     356      14    1695     69f i8259_32.o.after

	Ingo