[patch 2/2] genirq: Remove IRQF_DISABLED from core code

Thomas Gleixner
2010-03-26T00:07:50Z

[-- Attachment #1: genirq-remove-irqf-disabled-from-core-code.patch --]
[-- Type: text/plain, Size: 3207 bytes --]

Remove all code which is related to IRQF_DISABLED from the core kernel
code. IRQF_DISABLED still exists as a flag, but becomes a NOOP and
will be removed after a grace period. That way we can easily revert to
the previous behaviour by just restoring the core code.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
---
Documentation/feature-removal-schedule.txt | 7 +++++++
include/linux/interrupt.h | 3 ++-
kernel/irq/manage.c | 20 --------------------
3 files changed, 9 insertions(+), 21 deletions(-)

Index: linux-2.6/Documentation/feature-removal-schedule.txt
===================================================================
--- linux-2.6.orig/Documentation/feature-removal-schedule.txt
+++ linux-2.6/Documentation/feature-removal-schedule.txt
@@ -589,3 +589,10 @@ Why: Useful in 2003, implementation is a
Generally invoked by accident today.
Seen as doing more harm than good.
Who: Len Brown <len.brown@intel.com>
+
+----------------------------
+
+What: IRQF_DISABLED
+When: 2.6.36
+Why: The flag is a NOOP as we run interrupt handlers with interrupts disabled
+Who: Thomas Gleixner <tglx@linutronix.de>
Index: linux-2.6/include/linux/interrupt.h
===================================================================
--- linux-2.6.orig/include/linux/interrupt.h
+++ linux-2.6/include/linux/interrupt.h
@@ -39,7 +39,8 @@
* These flags used only by the kernel as part of the
* irq handling routines.
*
- * IRQF_DISABLED - keep irqs disabled when calling the action handler
+ * IRQF_DISABLED - keep irqs disabled when calling the action handler.
+ * DEPRECATED. This flag is a NOOP and scheduled to be removed
* IRQF_SAMPLE_RANDOM - irq is used to feed the random generator
* IRQF_SHARED - allow sharing the irq among several devices
* IRQF_PROBE_SHARED - set by callers when they expect sharing mismatches to occur
Index: linux-2.6/kernel/irq/manage.c
===================================================================
--- linux-2.6.orig/kernel/irq/manage.c
+++ linux-2.6/kernel/irq/manage.c
@@ -995,7 +995,6 @@ EXPORT_SYMBOL(free_irq);
* Flags:
*
* IRQF_SHARED Interrupt is shared
- * IRQF_DISABLED Disable local interrupts while processing
* IRQF_SAMPLE_RANDOM The interrupt can be used for entropy
* IRQF_TRIGGER_* Specify active edge(s) or level
*
@@ -1009,25 +1008,6 @@ int request_threaded_irq(unsigned int ir
int retval;

/*
- * handle_IRQ_event() always ignores IRQF_DISABLED except for
- * the _first_ irqaction (sigh). That can cause oopsing, but
- * the behavior is classified as "will not fix" so we need to
- * start nudging drivers away from using that idiom.
- */
- if ((irqflags & (IRQF_SHARED|IRQF_DISABLED)) ==
- (IRQF_SHARED|IRQF_DISABLED)) {
- pr_warning(
- "IRQ %d/%s: IRQF_DISABLED is not guaranteed on shared IRQs\n",
- irq, devname);
- }
-
-#ifdef CONFIG_LOCKDEP
- /*
- * Lockdep wants atomic interrupt handlers:
- */
- irqflags |= IRQF_DISABLED;
-#endif
- /*
* Sanity-check: shared interrupts must pass in a real dev-ID,
* otherwise we'll have trouble later trying to figure out
* which interrupt is which (messes up the interrupt freeing