[PATCH 4.19 19/46] gpiolib-acpi: Only defer request_irq for GpioInt ACPI event handlers

From: Greg Kroah-Hartman
Date: Fri Dec 28 2018 - 06:53:38 EST


4.19-stable review patch. If anyone has any objections, please let me know.

------------------

From: Hans de Goede <hdegoede@xxxxxxxxxx>

commit e59f5e08ece1060073d92c66ded52e1f2c43b5bb upstream.

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@xxxxxxxxxxxxxxx
Fixes: 78d3a92edbfb ("gpiolib-acpi: Register GpioInt ACPI event ...")
Signed-off-by: Hans de Goede <hdegoede@xxxxxxxxxx>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@xxxxxxxxxxxxxxx>
Acked-by: Mika Westerberg <mika.westerberg@xxxxxxxxxxxxxxx>
Signed-off-by: Linus Walleij <linus.walleij@xxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>

---
drivers/gpio/gpiolib-acpi.c | 144 +++++++++++++++++++++++++-------------------
1 file changed, 84 insertions(+), 60 deletions(-)

--- a/drivers/gpio/gpiolib-acpi.c
+++ b/drivers/gpio/gpiolib-acpi.c
@@ -23,11 +23,28 @@

#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;
};

@@ -53,10 +70,10 @@ 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);
@@ -137,8 +154,42 @@ bool acpi_gpio_get_irq_resource(struct a
}
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;
@@ -147,8 +198,7 @@ static acpi_status acpi_gpiochip_request
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;
@@ -179,8 +229,6 @@ static acpi_status acpi_gpiochip_request

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");
@@ -193,64 +241,42 @@ static acpi_status acpi_gpiochip_request
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:
@@ -287,6 +313,9 @@ void acpi_gpiochip_request_interrupts(st
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)
@@ -297,8 +326,7 @@ void acpi_gpiochip_request_interrupts(st
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);

@@ -335,10 +363,13 @@ void acpi_gpiochip_free_interrupts(struc
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;
@@ -1204,23 +1235,16 @@ bool acpi_can_fallback_to_crs(struct acp
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);
@@ -1228,4 +1252,4 @@ static int acpi_gpio_handle_deferred_req
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);