Commit 78d3a92edbfb ("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: 78d3a92edbfb ("gpiolib-acpi: Register GpioInt ACPI event ...") Signed-off-by: Hans de Goede hdegoede@redhat.com --- Changes in v2: -add kernel-doc describing struct acpi_gpio_event members (requested by Mika) -s/acpi_gpiochip_request_interrupt_desc/acpi_gpiochip_alloc_event/ (req Mika) -minor style fixups (requested by Andy) --- drivers/gpio/gpiolib-acpi.c | 144 +++++++++++++++++++++--------------- 1 file changed, 84 insertions(+), 60 deletions(-)

diff --git a/drivers/gpio/gpiolib-acpi.c b/drivers/gpio/gpiolib-acpi.c index 55b72fbe1631..7f93954c58ea 100644 --- a/drivers/gpio/gpiolib-acpi.c +++ b/drivers/gpio/gpiolib-acpi.c @@ -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); @@ -133,8 +150,42 @@ 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, - void *context) +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; struct gpio_chip *chip = acpi_gpio->chip; @@ -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 | - IRQF_TRIGGER_FALLING; + 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))) - disable_irq_wake(event->irq); + if (event->irq_requested) { + if (event->irq_is_wake) + disable_irq_wake(event->irq); + + free_irq(event->irq, event); + }

- 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);