genirq: keep affinities set from userspace across free/request_irq()
Impact: preserve user-modified affinities on interrupts
Kumar Galak noticed that commit
18404756765c713a0be4eb1082920c04822ce588 (genirq: Expose default irq
affinity mask (take 3))
overrides an already set affinity setting across a free /
request_irq(). Happens e.g. with ifdown/ifup of a network device.
Change the logic to mark the affinities as set and keep them
intact. This also fixes the unlocked access to irq_desc in
irq_select_affinity() when called from irq_affinity_proc_write()
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
diff --git a/kernel/irq/internals.h b/kernel/irq/internals.h
index c9767e6..64c1c72 100644
--- a/kernel/irq/internals.h
+++ b/kernel/irq/internals.h
@@ -25,6 +25,8 @@
struct irqaction *action) { }
#endif
+extern int irq_select_affinity_usr(unsigned int irq);
+
/*
* Debugging printout:
*/
