Re: 2.6.20->2.6.21 - networking dies after random time

Ingo Molnar
2007-07-24T09:42:57Z

* Ingo Molnar <mingo@elte.hu> wrote:

> thanks for tracking it down! Could you try the patch below (ontop an
> otherwise unmodified kernel)? This tests the theory whether the
> problem is related to the disable_irq_nosync() call in the ne2k
> driver's xmit path. Does this solve the hangs too?

please try the patch below instead.

Ingo

Index: linux/kernel/irq/chip.c
===================================================================
--- linux.orig/kernel/irq/chip.c
+++ linux/kernel/irq/chip.c
@@ -231,7 +231,7 @@ static void default_enable(unsigned int
/*
* default disable function
*/
-static void default_disable(unsigned int irq)
+void default_disable(unsigned int irq)
{
}

Index: linux/kernel/irq/internals.h
===================================================================
--- linux.orig/kernel/irq/internals.h
+++ linux/kernel/irq/internals.h
@@ -10,6 +10,8 @@ extern void irq_chip_set_defaults(struct
/* Set default handler: */
extern void compat_irq_chip_set_default_handler(struct irq_desc *desc);

+extern void default_disable(unsigned int irq);
+
#ifdef CONFIG_PROC_FS
extern void register_irq_proc(unsigned int irq);
extern void register_handler_proc(unsigned int irq, struct irqaction *action);
Index: linux/kernel/irq/manage.c
===================================================================
--- linux.orig/kernel/irq/manage.c
+++ linux/kernel/irq/manage.c
@@ -102,7 +102,19 @@ void disable_irq_nosync(unsigned int irq
spin_lock_irqsave(&desc->lock, flags);
if (!desc->depth++) {
desc->status |= IRQ_DISABLED;
- desc->chip->disable(irq);
+ /*
+ * the _nosync variant of irq-disable suggests that the
+ * caller is not worried about concurrency but about the
+ * ordering of the irq flow itself. (such as hardware
+ * getting confused about certain, normally valid irq
+ * handling sequences.) So if the default disable handler
+ * is in place then try the more conservative masking
+ * instead:
+ */
+ if (desc->chip->disable == default_disable && desc->chip->mask)
+ desc->chip->mask(irq);
+ else
+ desc->chip->disable(irq);
}
spin_unlock_irqrestore(&desc->lock, flags);
}