kernel/irq: Extend lockdep class for request mutex

The IRQ code already has support for lockdep class for the lock mutex
in an interrupt descriptor. Extend this to add a second class for the
request mutex in the descriptor. Not having a class is resulting in
false positive splats in some code paths.

Signed-off-by: Andrew Lunn <andrew@lunn.ch>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: linus.walleij@linaro.org
Cc: grygorii.strashko@ti.com
Cc: f.fainelli@gmail.com
Link: https://lkml.kernel.org/r/1512234664-21555-1-git-send-email-andrew@lunn.ch

1 files changed, 7 insertions, 4 deletions

diff --git a/kernel/irq/generic-chip.c b/kernel/irq/generic-chip.c
index c26c5bb6b491..508c03dfef25 100644
--- a/kernel/irq/generic-chip.c
+++ b/kernel/irq/generic-chip.c
@@ -364,10 +364,11 @@ irq_get_domain_generic_chip(struct irq_domain *d, unsigned int hw_irq)
 EXPORT_SYMBOL_GPL(irq_get_domain_generic_chip);
 
 /*
- * Separate lockdep class for interrupt chip which can nest irq_desc
- * lock.
+ * Separate lockdep classes for interrupt chip which can nest irq_desc
+ * lock and request mutex.
  */
 static struct lock_class_key irq_nested_lock_class;
+static struct lock_class_key irq_nested_request_class;
 
 /*
  * irq_map_generic_chip - Map a generic chip for an irq domain
@@ -409,7 +410,8 @@ int irq_map_generic_chip(struct irq_domain *d, unsigned int virq,
         set_bit(idx, &gc->installed);
 
         if (dgc->gc_flags & IRQ_GC_INIT_NESTED_LOCK)
-                irq_set_lockdep_class(virq, &irq_nested_lock_class);
+                irq_set_lockdep_class(virq, &irq_nested_lock_class,
+                                      &irq_nested_request_class);
 
         if (chip->irq_calc_mask)
                 chip->irq_calc_mask(data);
@@ -479,7 +481,8 @@ void irq_setup_generic_chip(struct irq_chip_generic *gc, u32 msk,
                         continue;
 
                 if (flags & IRQ_GC_INIT_NESTED_LOCK)
-                        irq_set_lockdep_class(i, &irq_nested_lock_class);
+                        irq_set_lockdep_class(i, &irq_nested_lock_class,
+                                              &irq_nested_request_class);
 
                 if (!(flags & IRQ_GC_NO_MASK)) {
                         struct irq_data *d = irq_get_irq_data(i);