Commit 201d7f47 authored by Thomas Gleixner's avatar Thomas Gleixner
Browse files

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: default avatarThomas Gleixner <tglx@linutronix.de>
Acked-by: default avatarMarc 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
parent 5a29ef22

include/linux/irq.h

+6 −0
Original line number Diff line number Diff line
@@ -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)

kernel/irq/chip.c

+54 −22
Original line number Diff line number Diff line
@@ -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;



	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);

	if (irqd_is_started(&desc->irq_data)) {

		desc->depth = 1;

	if (desc->irq_data.chip->irq_shutdown)

		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);

	irq_domain_deactivate_irq(&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);

}



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)

kernel/irq/manage.c

+9 −3
Original line number Diff line number Diff line
@@ -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--;

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