The patch titled
Debug shared irqs
has been removed from the -mm tree. Its filename was
debug-shared-irqs.patch
This patch was dropped because it was merged into mainline or a subsystem tree
------------------------------------------------------
Subject: Debug shared irqs
From: David Woodhouse <dwmw2@xxxxxxxxxxxxx>
Drivers registering IRQ handlers with SA_SHIRQ really ought to be able to
handle an interrupt happening before request_irq() returns. They also
ought to be able to handle an interrupt happening during the start of their
call to free_irq(). Let's test that hypothesis....
[bunk@xxxxxxxxx: Kconfig fixes]
Signed-off-by: David Woodhouse <dwmw2@xxxxxxxxxxxxx>
Cc: Arjan van de Ven <arjan@xxxxxxxxxxxxx>
Signed-off-by: Jesper Juhl <jesper.juhl@xxxxxxxxx>
Signed-off-by: Ingo Molnar <mingo@xxxxxxx>
Signed-off-by: Adrian Bunk <bunk@xxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
kernel/irq/manage.c | 33 +++++++++++++++++++++++++++++++++
lib/Kconfig.debug | 9 +++++++++
2 files changed, 42 insertions(+)
diff -puN kernel/irq/manage.c~debug-shared-irqs kernel/irq/manage.c
--- a/kernel/irq/manage.c~debug-shared-irqs
+++ a/kernel/irq/manage.c
@@ -357,6 +357,7 @@ void free_irq(unsigned int irq, void *de
struct irq_desc *desc;
struct irqaction **p;
unsigned long flags;
+ irqreturn_t (*handler)(int, void *) = NULL;
WARN_ON(in_interrupt());
if (irq >= NR_IRQS)
@@ -396,6 +397,8 @@ void free_irq(unsigned int irq, void *de
/* Make sure it's not being used on another CPU */
synchronize_irq(irq);
+ if (action->flags & IRQF_SHARED)
+ handler = action->handler;
kfree(action);
return;
}
@@ -403,6 +406,17 @@ void free_irq(unsigned int irq, void *de
spin_unlock_irqrestore(&desc->lock, flags);
return;
}
+#ifdef CONFIG_DEBUG_SHIRQ
+ if (handler) {
+ /*
+ * It's a shared IRQ -- the driver ought to be prepared for it
+ * to happen even now it's being freed, so let's make sure....
+ * We do this after actually deregistering it, to make sure that
+ * a 'real' IRQ doesn't run in parallel with our fake
+ */
+ handler(irq, dev_id);
+ }
+#endif
}
EXPORT_SYMBOL(free_irq);
@@ -475,6 +489,25 @@ int request_irq(unsigned int irq, irq_ha
select_smp_affinity(irq);
+#ifdef CONFIG_DEBUG_SHIRQ
+ if (irqflags & IRQF_SHARED) {
+ /*
+ * It's a shared IRQ -- the driver ought to be prepared for it
+ * to happen immediately, so let's make sure....
+ * We do this before actually registering it, to make sure that
+ * a 'real' IRQ doesn't run in parallel with our fake
+ */
+ if (irqflags & IRQF_DISABLED) {
+ unsigned long flags;
+
+ local_irq_save(flags);
+ handler(irq, dev_id);
+ local_irq_restore(flags);
+ } else
+ handler(irq, dev_id);
+ }
+#endif
+
retval = setup_irq(irq, action);
if (retval)
kfree(action);
diff -puN lib/Kconfig.debug~debug-shared-irqs lib/Kconfig.debug
--- a/lib/Kconfig.debug~debug-shared-irqs
+++ a/lib/Kconfig.debug
@@ -77,6 +77,15 @@ config DEBUG_KERNEL
Say Y here if you are developing drivers or trying to debug and
identify kernel problems.
+config DEBUG_SHIRQ
+ bool "Debug shared IRQ handlers"
+ depends on DEBUG_KERNEL && GENERIC_HARDIRQS
+ help
+ Enable this to generate a spurious interrupt as soon as a shared
+ interrupt handler is registered, and just before one is deregistered.
+ Drivers ought to be able to handle interrupts coming in at those
+ points; some don't and need to be caught.
+
config LOG_BUF_SHIFT
int "Kernel log buffer size (16 => 64KB, 17 => 128KB)" if DEBUG_KERNEL
range 12 21
_
Patches currently in -mm which might be from dwmw2@xxxxxxxxxxxxx are
origin.patch
new-toplevel-target-headers_check_all.patch
git-mtd.patch
-
To unsubscribe from this list: send the line "unsubscribe mm-commits" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
