[PATCH] pseries: don't die if unknown/missing interrupt controller property

The pseries platform does not have a default function for init_IRQ and
does not install one if it doesn't find or doesn't recognize an
interrupt controller in the device tree.  Currently, the kernel dies
when it tries to call the NULL init_IRQ() function.  Clean that up.

Signed-off-by: Sonny Rao <redacted>

--- kernel/arch/powerpc/platforms/pseries/setup.c~orig	2007-06-26 16:23:38.000000000 -0500
+++ kernel/arch/powerpc/platforms/pseries/setup.c	2007-06-26 19:09:53.000000000 -0500

@@ -274,6 +274,12 @@ static void pseries_lpar_enable_pmcs(voi
 		get_lppaca()->pmcregs_in_use = 1;
 }
 
+static void no_irq_init(void)
+{
+	printk(KERN_ERR "no_irq_init: failed to recognize"
+	       " interrupt-controller\n");
+}
+
 static void __init pseries_discover_pic(void)
 {
 	struct device_node *np;

@@ -296,8 +302,6 @@ static void __init pseries_discover_pic(
 			return;
 		}
 	}
-	printk(KERN_ERR "pSeries_discover_pic: failed to recognize"
-	       " interrupt-controller\n");
 }
 
 static void __init pSeries_setup_arch(void)

@@ -594,4 +598,5 @@ define_machine(pseries) {
 	.check_legacy_ioport	= pSeries_check_legacy_ioport,
 	.system_reset_exception = pSeries_system_reset_exception,
 	.machine_check_exception = pSeries_machine_check_exception,
+	.init_IRQ		= no_irq_init,  
 };

On Sun, Jul 01, 2007 at 08:49:37PM -0400, Sonny Rao wrote:

Hi Paul, if there's no objection I'd like this to go into 2.6.23 thanks.

On Sun, Jul 01, 2007 at 08:49:37PM -0400, Sonny Rao wrote:

The pseries platform does not have a default function for init_IRQ and
does not install one if it doesn't find or doesn't recognize an
interrupt controller in the device tree.  Currently, the kernel dies
when it tries to call the NULL init_IRQ() function.  Clean that up.

Doesn't it make more sense to make init_IRQ() check that the pointer is
set instead? That'll work for more platforms than just pseries.


-Olof

On Thu, Jul 05, 2007 at 08:37:34AM -0500, Olof Johansson wrote:

On Sun, Jul 01, 2007 at 08:49:37PM -0400, Sonny Rao wrote:

quoted

The pseries platform does not have a default function for init_IRQ and
does not install one if it doesn't find or doesn't recognize an
interrupt controller in the device tree.  Currently, the kernel dies
when it tries to call the NULL init_IRQ() function.  Clean that up.

Doesn't it make more sense to make init_IRQ() check that the pointer is
set instead? That'll work for more platforms than just pseries.

Yeah, that might be the simplest way.  The only reason I can think of
to do it this way is that (I think) every single other platform in
arch/powerpc statically initializes init_IRQ, with pseries being the
oddball.  It doesn't matter much to me, so I can post another patch in a
bit.

Sonny

On Fri, Jul 06, 2007 at 05:16:34AM -0400, Sonny Rao wrote:

On Thu, Jul 05, 2007 at 08:37:34AM -0500, Olof Johansson wrote:

quoted

On Sun, Jul 01, 2007 at 08:49:37PM -0400, Sonny Rao wrote:

quoted

The pseries platform does not have a default function for init_IRQ and
does not install one if it doesn't find or doesn't recognize an
interrupt controller in the device tree.  Currently, the kernel dies
when it tries to call the NULL init_IRQ() function.  Clean that up.

Doesn't it make more sense to make init_IRQ() check that the pointer is
set instead? That'll work for more platforms than just pseries.

Yeah, that might be the simplest way.  The only reason I can think of
to do it this way is that (I think) every single other platform in
arch/powerpc statically initializes init_IRQ, with pseries being the
oddball.  It doesn't matter much to me, so I can post another patch in a
bit.

Check to make sure ppc_md.init_IRQ exists before calling it.

Signed-off-by: Sonny Rao <redacted>

--- linux/arch/powerpc/kernel/irq.c~orig 2007-07-09 12:46:58.000000000 -0500
+++ linux/arch/powerpc/kernel/irq.c 2007-07-09 12:47:07.000000000 -0500

@@ -337,8 +337,8 @@ void do_IRQ(struct pt_regs *regs)
 
 void __init init_IRQ(void)
 {
-
-	ppc_md.init_IRQ();
+	if (ppc_md.init_IRQ)
+		ppc_md.init_IRQ();
 #ifdef CONFIG_PPC64
 	irq_ctx_init();
 #endif