genirq: Handle pending irqs in irq_startup()

commit b4bc724e82e80478cba5fe9825b62e71ddf78757 upstream.

An interrupt might be pending when irq_startup() is called, but the
startup code does not invoke the resend logic. In some cases this
prevents the device from issuing another interrupt which renders the
device non functional.

Call the resend function in irq_startup() to keep things going.

Reported-and-tested-by: Russell King <rmk+kernel@arm.linux.org.uk>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/kernel/irq/autoprobe.c b/kernel/irq/autoprobe.c
index 342d8f44e4010d13cb03f21b89a57d9dc955497e..0119b9d467ae6dd1d53b9f38bcf9c95d63f7ae9d 100644 (file)
--- a/kernel/irq/autoprobe.c
+++ b/kernel/irq/autoprobe.c
@@ -53,7 +53,7 @@ unsigned long probe_irq_on(void)
                        if (desc->irq_data.chip->irq_set_type)
                                desc->irq_data.chip->irq_set_type(&desc->irq_data,
                                                         IRQ_TYPE_PROBE);
-                       irq_startup(desc);
+                       irq_startup(desc, false);
                }
                raw_spin_unlock_irq(&desc->lock);
        }
@@ -70,7 +70,7 @@ unsigned long probe_irq_on(void)
                raw_spin_lock_irq(&desc->lock);
                if (!desc->action && irq_settings_can_probe(desc)) {
                        desc->istate |= IRQS_AUTODETECT | IRQS_WAITING;
-                       if (irq_startup(desc))
+                       if (irq_startup(desc, false))
                                desc->istate |= IRQS_PENDING;
                }
                raw_spin_unlock_irq(&desc->lock);

diff --git a/kernel/irq/chip.c b/kernel/irq/chip.c
index 3322a34d9ee2e48a35fdea8b60c66417bcc08880..ca14f5dcabde94ff8126d59e334fb7d1dc2b9699 100644 (file)
--- a/kernel/irq/chip.c
+++ b/kernel/irq/chip.c
@@ -157,19 +157,22 @@ static void irq_state_set_masked(struct irq_desc *desc)
        irqd_set(&desc->irq_data, IRQD_IRQ_MASKED);
 }
 
-int irq_startup(struct irq_desc *desc)
+int irq_startup(struct irq_desc *desc, bool resend)
 {
+       int ret = 0;
+
        irq_state_clr_disabled(desc);
        desc->depth = 0;
 
        if (desc->irq_data.chip->irq_startup) {
-               int ret = desc->irq_data.chip->irq_startup(&desc->irq_data);
+               ret = desc->irq_data.chip->irq_startup(&desc->irq_data);
                irq_state_clr_masked(desc);
-               return ret;
+       } else {
+               irq_enable(desc);
        }
-
-       irq_enable(desc);
-       return 0;
+       if (resend)
+               check_irq_resend(desc, desc->irq_data.irq);
+       return ret;
 }
 
 void irq_shutdown(struct irq_desc *desc)
@@ -596,7 +599,7 @@ __irq_set_handler(unsigned int irq, irq_flow_handler_t handle, int is_chained,
                irq_settings_set_noprobe(desc);
                irq_settings_set_norequest(desc);
                irq_settings_set_nothread(desc);
-               irq_startup(desc);
+               irq_startup(desc, true);
        }
 out:
        irq_put_desc_busunlock(desc, flags);

diff --git a/kernel/irq/internals.h b/kernel/irq/internals.h
index 6546431447d766396b371595f6d46df41c883c9a..62efdc44b64309f3665f85117f30d247de61f716 100644 (file)
--- a/kernel/irq/internals.h
+++ b/kernel/irq/internals.h
@@ -67,7 +67,7 @@ extern int __irq_set_trigger(struct irq_desc *desc, unsigned int irq,
 extern void __disable_irq(struct irq_desc *desc, unsigned int irq, bool susp);
 extern void __enable_irq(struct irq_desc *desc, unsigned int irq, bool resume);
 
-extern int irq_startup(struct irq_desc *desc);
+extern int irq_startup(struct irq_desc *desc, bool resend);
 extern void irq_shutdown(struct irq_desc *desc);
 extern void irq_enable(struct irq_desc *desc);
 extern void irq_disable(struct irq_desc *desc);

diff --git a/kernel/irq/manage.c b/kernel/irq/manage.c
index a1aadab09aab9476ae0f15bce762790367154172..def3406fb43b91234a6398c145ecb6e08e7e5cf9 100644 (file)
--- a/kernel/irq/manage.c
+++ b/kernel/irq/manage.c
@@ -1018,7 +1018,7 @@ __setup_irq(unsigned int irq, struct irq_desc *desc, struct irqaction *new)
                        desc->istate |= IRQS_ONESHOT;
 
                if (irq_settings_can_autoenable(desc))
-                       irq_startup(desc);
+                       irq_startup(desc, true);
                else
                        /* Undo nested disables: */
                        desc->depth = 1;