[PATCH] sparseirq: fix hang with !SPARSE_IRQ

[PATCH] sparseirq: fix hang with !SPARSE_IRQ

[Yinghai Lu]

Impact: fix hang

Suresh report his two sockets system only works with SPARSE_IRQ enable
it turns out we miss the setting desc->irq

so provide early_irq_init() even !SPARSE_IRQ to set desc->irq

Reported by: "Siddha, Suresh B" <suresh.b.siddha@intel.com>
Signed-off-by: Yinghai Lu <yinghai@kernel.org>

---
 init/main.c         |    6 ------
 kernel/irq/handle.c |   15 +++++++++++++++
 2 files changed, 15 insertions(+), 6 deletions(-)

Index: linux-2.6/kernel/irq/handle.c
===================================================================
--- linux-2.6.orig/kernel/irq/handle.c
+++ linux-2.6/kernel/irq/handle.c
@@ -218,6 +218,21 @@ struct irq_desc irq_desc[NR_IRQS] __cach
 	}
 };
 
+void __init early_irq_init(void)
+{
+	struct irq_desc *desc;
+	int count;
+	int i;
+
+	desc = irq_desc;
+	count = ARRAY_SIZE(irq_desc);
+
+	for (i = 0; i < count; i++)
+		desc[i].irq = i;
+
+	arch_early_irq_init();
+}
+
 struct irq_desc *irq_to_desc(unsigned int irq)
 {
 	return (irq < NR_IRQS) ? irq_desc + irq : NULL;
Index: linux-2.6/init/main.c
===================================================================
--- linux-2.6.orig/init/main.c
+++ linux-2.6/init/main.c
@@ -549,15 +549,9 @@ void __init __weak thread_info_cache_ini
 	barrier();
 }
 
-void __init __weak arch_early_irq_init(void)
-{
-	barrier();
-}
-
 void __init __weak early_irq_init(void)
 {
 	barrier();
-	arch_early_irq_init();
 }
 
 asmlinkage void __init start_kernel(void)

Re: [PATCH] sparseirq: fix hang with !SPARSE_IRQ

[Ingo Molnar]

* Yinghai Lu <yinghai@kernel.org> wrote:

> Impact: fix hang
> 
> Suresh report his two sockets system only works with SPARSE_IRQ enable
> it turns out we miss the setting desc->irq
> 
> so provide early_irq_init() even !SPARSE_IRQ to set desc->irq
> 
> Reported by: "Siddha, Suresh B" <suresh.b.siddha@intel.com>
> Signed-off-by: Yinghai Lu <yinghai@kernel.org>
> 
> ---
>  init/main.c         |    6 ------
>  kernel/irq/handle.c |   15 +++++++++++++++
>  2 files changed, 15 insertions(+), 6 deletions(-)

applied to tip/irq/sparseirq - thanks Yinghai. This fixed a testsystem of 
mine as well that showed weird hangs with !sparseirq.

	Ingo