Commit e59f5e08 authored by Hans de Goede's avatar Hans de Goede Committed by Linus Walleij
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gpiolib-acpi: Only defer request_irq for GpioInt ACPI event handlers 



Commit 78d3a92e ("gpiolib-acpi: Register GpioInt ACPI event handlers
from a late_initcall") deferred the entire acpi_gpiochip_request_interrupt
call for each event resource.

This means it also delays the gpiochip_request_own_desc(..., "ACPI:Event")
call. This is a problem if some AML code reads the GPIO pin before we
run the deferred acpi_gpiochip_request_interrupt, because in that case
acpi_gpio_adr_space_handler() will already have called
gpiochip_request_own_desc(..., "ACPI:OpRegion") causing the call from
acpi_gpiochip_request_interrupt to fail with -EBUSY and we will fail to
register an event handler.

acpi_gpio_adr_space_handler is prepared for acpi_gpiochip_request_interrupt
already having claimed the pin, but the other way around does not work.

One example of a problem this causes, is the event handler for the OTG
ID pin on a Prowise PT301 tablet not registering, keeping the port stuck
in whatever mode it was in during boot and e.g. only allowing charging
after a reboot.

This commit fixes this by only deferring the request_irq call and the
initial run of edge-triggered IRQs instead of deferring all of
acpi_gpiochip_request_interrupt.

Cc: stable@vger.kernel.org
Fixes: 78d3a92e ("gpiolib-acpi: Register GpioInt ACPI event ...")
Signed-off-by: default avatarHans de Goede <hdegoede@redhat.com>
Reviewed-by: default avatarAndy Shevchenko <andriy.shevchenko@linux.intel.com>
Acked-by: default avatarMika Westerberg <mika.westerberg@linux.intel.com>
Signed-off-by: default avatarLinus Walleij <linus.walleij@linaro.org>
parent 2e6e902d

drivers/gpio/gpiolib-acpi.c

+84 −60
Original line number Diff line number Diff line
@@ -19,11 +19,28 @@ 


#include "gpiolib.h"



/**

 * struct acpi_gpio_event - ACPI GPIO event handler data

 *

 * @node:	  list-entry of the events list of the struct acpi_gpio_chip

 * @handle:	  handle of ACPI method to execute when the IRQ triggers

 * @handler:	  irq_handler to pass to request_irq when requesting the IRQ

 * @pin:	  GPIO pin number on the gpio_chip

 * @irq:	  Linux IRQ number for the event, for request_ / free_irq

 * @irqflags:     flags to pass to request_irq when requesting the IRQ

 * @irq_is_wake:  If the ACPI flags indicate the IRQ is a wakeup source

 * @is_requested: True if request_irq has been done

 * @desc:	  gpio_desc for the GPIO pin for this event

 */

struct acpi_gpio_event {

	struct list_head node;

	acpi_handle handle;

	irq_handler_t handler;

	unsigned int pin;

	unsigned int irq;

	unsigned long irqflags;

	bool irq_is_wake;

	bool irq_requested;

	struct gpio_desc *desc;

};
@@ -49,10 +66,10 @@ struct acpi_gpio_chip { 


/*

 * For gpiochips which call acpi_gpiochip_request_interrupts() before late_init

 * (so builtin drivers) we register the ACPI GpioInt event handlers from a

 * (so builtin drivers) we register the ACPI GpioInt IRQ handlers from a

 * late_initcall_sync handler, so that other builtin drivers can register their

 * OpRegions before the event handlers can run.  This list contains gpiochips

 * for which the acpi_gpiochip_request_interrupts() has been deferred.

 * for which the acpi_gpiochip_request_irqs() call has been deferred.

 */

static DEFINE_MUTEX(acpi_gpio_deferred_req_irqs_lock);

static LIST_HEAD(acpi_gpio_deferred_req_irqs_list);
@@ -133,7 +150,41 @@ bool acpi_gpio_get_irq_resource(struct acpi_resource *ares, 
}

EXPORT_SYMBOL_GPL(acpi_gpio_get_irq_resource);



static acpi_status acpi_gpiochip_request_interrupt(struct acpi_resource *ares,

static void acpi_gpiochip_request_irq(struct acpi_gpio_chip *acpi_gpio,

				      struct acpi_gpio_event *event)

{

	int ret, value;



	ret = request_threaded_irq(event->irq, NULL, event->handler,

				   event->irqflags, "ACPI:Event", event);

	if (ret) {

		dev_err(acpi_gpio->chip->parent,

			"Failed to setup interrupt handler for %d\n",

			event->irq);

		return;

	}



	if (event->irq_is_wake)

		enable_irq_wake(event->irq);



	event->irq_requested = true;



	/* Make sure we trigger the initial state of edge-triggered IRQs */

	value = gpiod_get_raw_value_cansleep(event->desc);

	if (((event->irqflags & IRQF_TRIGGER_RISING) && value == 1) ||

	    ((event->irqflags & IRQF_TRIGGER_FALLING) && value == 0))

		event->handler(event->irq, event);

}



static void acpi_gpiochip_request_irqs(struct acpi_gpio_chip *acpi_gpio)

{

	struct acpi_gpio_event *event;



	list_for_each_entry(event, &acpi_gpio->events, node)

		acpi_gpiochip_request_irq(acpi_gpio, event);

}



static acpi_status acpi_gpiochip_alloc_event(struct acpi_resource *ares,

					     void *context)

{

	struct acpi_gpio_chip *acpi_gpio = context;
@@ -143,8 +194,7 @@ static acpi_status acpi_gpiochip_request_interrupt(struct acpi_resource *ares, 
	struct acpi_gpio_event *event;

	irq_handler_t handler = NULL;

	struct gpio_desc *desc;

	unsigned long irqflags;

	int ret, pin, irq, value;

	int ret, pin, irq;



	if (!acpi_gpio_get_irq_resource(ares, &agpio))

		return AE_OK;
@@ -175,8 +225,6 @@ static acpi_status acpi_gpiochip_request_interrupt(struct acpi_resource *ares, 


	gpiod_direction_input(desc);



	value = gpiod_get_value_cansleep(desc);



	ret = gpiochip_lock_as_irq(chip, pin);

	if (ret) {

		dev_err(chip->parent, "Failed to lock GPIO as interrupt\n");
@@ -189,64 +237,42 @@ static acpi_status acpi_gpiochip_request_interrupt(struct acpi_resource *ares, 
		goto fail_unlock_irq;

	}



	irqflags = IRQF_ONESHOT;

	event = kzalloc(sizeof(*event), GFP_KERNEL);

	if (!event)

		goto fail_unlock_irq;



	event->irqflags = IRQF_ONESHOT;

	if (agpio->triggering == ACPI_LEVEL_SENSITIVE) {

		if (agpio->polarity == ACPI_ACTIVE_HIGH)

			irqflags |= IRQF_TRIGGER_HIGH;

			event->irqflags |= IRQF_TRIGGER_HIGH;

		else

			irqflags |= IRQF_TRIGGER_LOW;

			event->irqflags |= IRQF_TRIGGER_LOW;

	} else {

		switch (agpio->polarity) {

		case ACPI_ACTIVE_HIGH:

			irqflags |= IRQF_TRIGGER_RISING;

			event->irqflags |= IRQF_TRIGGER_RISING;

			break;

		case ACPI_ACTIVE_LOW:

			irqflags |= IRQF_TRIGGER_FALLING;

			event->irqflags |= IRQF_TRIGGER_FALLING;

			break;

		default:

			irqflags |= IRQF_TRIGGER_RISING |

			event->irqflags |= IRQF_TRIGGER_RISING |

					   IRQF_TRIGGER_FALLING;

			break;

		}

	}



	event = kzalloc(sizeof(*event), GFP_KERNEL);

	if (!event)

		goto fail_unlock_irq;



	event->handle = evt_handle;

	event->handler = handler;

	event->irq = irq;

	event->irq_is_wake = agpio->wake_capable == ACPI_WAKE_CAPABLE;

	event->pin = pin;

	event->desc = desc;



	ret = request_threaded_irq(event->irq, NULL, handler, irqflags,

				   "ACPI:Event", event);

	if (ret) {

		dev_err(chip->parent,

			"Failed to setup interrupt handler for %d\n",

			event->irq);

		goto fail_free_event;

	}



	if (agpio->wake_capable == ACPI_WAKE_CAPABLE)

		enable_irq_wake(irq);



	list_add_tail(&event->node, &acpi_gpio->events);



	/*

	 * Make sure we trigger the initial state of the IRQ when using RISING

	 * or FALLING.  Note we run the handlers on late_init, the AML code

	 * may refer to OperationRegions from other (builtin) drivers which

	 * may be probed after us.

	 */

	if (((irqflags & IRQF_TRIGGER_RISING) && value == 1) ||

	    ((irqflags & IRQF_TRIGGER_FALLING) && value == 0))

		handler(event->irq, event);



	return AE_OK;



fail_free_event:

	kfree(event);

fail_unlock_irq:

	gpiochip_unlock_as_irq(chip, pin);

fail_free_desc:
@@ -283,6 +309,9 @@ void acpi_gpiochip_request_interrupts(struct gpio_chip *chip) 
	if (ACPI_FAILURE(status))

		return;



	acpi_walk_resources(handle, "_AEI",

			    acpi_gpiochip_alloc_event, acpi_gpio);



	mutex_lock(&acpi_gpio_deferred_req_irqs_lock);

	defer = !acpi_gpio_deferred_req_irqs_done;

	if (defer)
@@ -293,8 +322,7 @@ void acpi_gpiochip_request_interrupts(struct gpio_chip *chip) 
	if (defer)

		return;



	acpi_walk_resources(handle, "_AEI",

			    acpi_gpiochip_request_interrupt, acpi_gpio);

	acpi_gpiochip_request_irqs(acpi_gpio);

}

EXPORT_SYMBOL_GPL(acpi_gpiochip_request_interrupts);
@@ -331,10 +359,13 @@ void acpi_gpiochip_free_interrupts(struct gpio_chip *chip) 
	list_for_each_entry_safe_reverse(event, ep, &acpi_gpio->events, node) {

		struct gpio_desc *desc;



		if (irqd_is_wakeup_set(irq_get_irq_data(event->irq)))

		if (event->irq_requested) {

			if (event->irq_is_wake)

				disable_irq_wake(event->irq);



			free_irq(event->irq, event);

		}



		desc = event->desc;

		if (WARN_ON(IS_ERR(desc)))

			continue;
@@ -1200,23 +1231,16 @@ bool acpi_can_fallback_to_crs(struct acpi_device *adev, const char *con_id) 
	return con_id == NULL;

}



/* Run deferred acpi_gpiochip_request_interrupts() */

static int acpi_gpio_handle_deferred_request_interrupts(void)

/* Run deferred acpi_gpiochip_request_irqs() */

static int acpi_gpio_handle_deferred_request_irqs(void)

{

	struct acpi_gpio_chip *acpi_gpio, *tmp;



	mutex_lock(&acpi_gpio_deferred_req_irqs_lock);

	list_for_each_entry_safe(acpi_gpio, tmp,

				 &acpi_gpio_deferred_req_irqs_list,

				 deferred_req_irqs_list_entry) {

		acpi_handle handle;



		handle = ACPI_HANDLE(acpi_gpio->chip->parent);

		acpi_walk_resources(handle, "_AEI",

				    acpi_gpiochip_request_interrupt, acpi_gpio);



		list_del_init(&acpi_gpio->deferred_req_irqs_list_entry);

	}

				 deferred_req_irqs_list_entry)

		acpi_gpiochip_request_irqs(acpi_gpio);



	acpi_gpio_deferred_req_irqs_done = true;

	mutex_unlock(&acpi_gpio_deferred_req_irqs_lock);
@@ -1224,4 +1248,4 @@ static int acpi_gpio_handle_deferred_request_interrupts(void) 
	return 0;

}

/* We must use _sync so that this runs after the first deferred_probe run */

late_initcall_sync(acpi_gpio_handle_deferred_request_interrupts);
 
late_initcall_sync(acpi_gpio_handle_deferred_request_irqs);

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