genirq: Handle NOAUTOEN interrupt setup proper

If an interrupt is marked NOAUTOEN then request_irq() installs the action,
but does not enable the interrupt via startup_irq().  The interrupt is
enabled via enable_irq() later from the driver. enable_irq() calls
irq_enable().

That means that for interrupts which have a irq_startup() callback this
callback is never invoked. Neither is irq_domain_activate_irq() invoked for
such interrupts.

If an interrupt depends on irq_startup() or irq_domain_activate_irq() then
the enable via irq_enable() is not enough.

Add a status flag IRQD_IRQ_STARTED_UP and use this to select the proper
mechanism in enable_irq(). Use the flag also to avoid pointless calls into
the low level functions.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Marc Zyngier <marc.zyngier@arm.com>
Cc: dianders@chromium.org
Cc: jeffy <jeffy.chen@rock-chips.com>
Cc: Brian Norris <briannorris@chromium.org>
Cc: tfiga@chromium.org
Link: http://lkml.kernel.org/r/20170531100212.130986205@linutronix.de

diff --git a/include/linux/irq.h b/include/linux/irq.h
index f887351aa80e787ddde2883f215cded0d18b6274..94d1ad6ffdd4f08198f3787f02f9a843e4981ef5 100644 (file)
--- a/include/linux/irq.h
+++ b/include/linux/irq.h
@@ -216,6 +216,7 @@ enum {
        IRQD_WAKEUP_ARMED               = (1 << 19),
        IRQD_FORWARDED_TO_VCPU          = (1 << 20),
        IRQD_AFFINITY_MANAGED           = (1 << 21),
+       IRQD_IRQ_STARTED                = (1 << 22),
 };
 
 #define __irqd_to_state(d) ACCESS_PRIVATE((d)->common, state_use_accessors)
@@ -329,6 +330,11 @@ static inline void irqd_clr_activated(struct irq_data *d)
        __irqd_to_state(d) &= ~IRQD_ACTIVATED;
 }
 
+static inline bool irqd_is_started(struct irq_data *d)
+{
+       return __irqd_to_state(d) & IRQD_IRQ_STARTED;
+}
+
 #undef __irqd_to_state
 
 static inline irq_hw_number_t irqd_to_hwirq(struct irq_data *d)

diff --git a/kernel/irq/chip.c b/kernel/irq/chip.c
index c94da688ee9b30ff9e746372b20a0c30f4c8cf5f..e0051d58c909fe2f77ebb8783eac53252f919ed6 100644 (file)
--- a/kernel/irq/chip.c
+++ b/kernel/irq/chip.c
@@ -185,37 +185,64 @@ static void irq_state_set_masked(struct irq_desc *desc)
        irqd_set(&desc->irq_data, IRQD_IRQ_MASKED);
 }
 
+static void irq_state_clr_started(struct irq_desc *desc)
+{
+       irqd_clear(&desc->irq_data, IRQD_IRQ_STARTED);
+}
+
+static void irq_state_set_started(struct irq_desc *desc)
+{
+       irqd_set(&desc->irq_data, IRQD_IRQ_STARTED);
+}
+
 int irq_startup(struct irq_desc *desc, bool resend)
 {
        int ret = 0;
 
-       irq_state_clr_disabled(desc);
        desc->depth = 0;
 
-       irq_domain_activate_irq(&desc->irq_data);
-       if (desc->irq_data.chip->irq_startup) {
-               ret = desc->irq_data.chip->irq_startup(&desc->irq_data);
-               irq_state_clr_masked(desc);
-       } else {
+       if (irqd_is_started(&desc->irq_data)) {
                irq_enable(desc);
+       } else {
+               irq_domain_activate_irq(&desc->irq_data);
+               if (desc->irq_data.chip->irq_startup) {
+                       ret = desc->irq_data.chip->irq_startup(&desc->irq_data);
+                       irq_state_clr_disabled(desc);
+                       irq_state_clr_masked(desc);
+               } else {
+                       irq_enable(desc);
+               }
+               irq_state_set_started(desc);
        }
+
        if (resend)
                check_irq_resend(desc);
+
        return ret;
 }
 
+static void __irq_disable(struct irq_desc *desc, bool mask);
+
 void irq_shutdown(struct irq_desc *desc)
 {
-       irq_state_set_disabled(desc);
-       desc->depth = 1;
-       if (desc->irq_data.chip->irq_shutdown)
-               desc->irq_data.chip->irq_shutdown(&desc->irq_data);
-       else if (desc->irq_data.chip->irq_disable)
-               desc->irq_data.chip->irq_disable(&desc->irq_data);
-       else
-               desc->irq_data.chip->irq_mask(&desc->irq_data);
+       if (irqd_is_started(&desc->irq_data)) {
+               desc->depth = 1;
+               if (desc->irq_data.chip->irq_shutdown) {
+                       desc->irq_data.chip->irq_shutdown(&desc->irq_data);
+                       irq_state_set_disabled(desc);
+                       irq_state_set_masked(desc);
+               } else {
+                       __irq_disable(desc, true);
+               }
+               irq_state_clr_started(desc);
+       }
+       /*
+        * This must be called even if the interrupt was never started up,
+        * because the activation can happen before the interrupt is
+        * available for request/startup. It has it's own state tracking so
+        * it's safe to call it unconditionally.
+        */
        irq_domain_deactivate_irq(&desc->irq_data);
-       irq_state_set_masked(desc);
 }
 
 void irq_enable(struct irq_desc *desc)
@@ -228,6 +255,17 @@ void irq_enable(struct irq_desc *desc)
        irq_state_clr_masked(desc);
 }
 
+static void __irq_disable(struct irq_desc *desc, bool mask)
+{
+       irq_state_set_disabled(desc);
+       if (desc->irq_data.chip->irq_disable) {
+               desc->irq_data.chip->irq_disable(&desc->irq_data);
+               irq_state_set_masked(desc);
+       } else if (mask) {
+               mask_irq(desc);
+       }
+}
+
 /**
  * irq_disable - Mark interrupt disabled
  * @desc:      irq descriptor which should be disabled
@@ -250,13 +288,7 @@ void irq_enable(struct irq_desc *desc)
  */
 void irq_disable(struct irq_desc *desc)
 {
-       irq_state_set_disabled(desc);
-       if (desc->irq_data.chip->irq_disable) {
-               desc->irq_data.chip->irq_disable(&desc->irq_data);
-               irq_state_set_masked(desc);
-       } else if (irq_settings_disable_unlazy(desc)) {
-               mask_irq(desc);
-       }
+       __irq_disable(desc, irq_settings_disable_unlazy(desc));
 }
 
 void irq_percpu_enable(struct irq_desc *desc, unsigned int cpu)

diff --git a/kernel/irq/manage.c b/kernel/irq/manage.c
index 070be980c37a57d91f86099d2be1b81db80176bc..57056109f1760431a9230c0fdfeea6bf9c1d5603 100644 (file)
--- a/kernel/irq/manage.c
+++ b/kernel/irq/manage.c
@@ -533,9 +533,15 @@ void __enable_irq(struct irq_desc *desc)
                        goto err_out;
                /* Prevent probing on this irq: */
                irq_settings_set_noprobe(desc);
-               irq_enable(desc);
-               check_irq_resend(desc);
-               /* fall-through */
+               /*
+                * Call irq_startup() not irq_enable() here because the
+                * interrupt might be marked NOAUTOEN. So irq_startup()
+                * needs to be invoked when it gets enabled the first
+                * time. If it was already started up, then irq_startup()
+                * will invoke irq_enable() under the hood.
+                */
+               irq_startup(desc, true);
+               break;
        }
        default:
                desc->depth--;