Hi,
On 26-11-18 13:39, Mika Westerberg wrote:
On Mon, Nov 26, 2018 at 11:42:31AM +0100, Hans de Goede wrote:
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>
---
drivers/gpio/gpiolib-acpi.c | 136 +++++++++++++++++++-----------------
1 file changed, 73 insertions(+), 63 deletions(-)
diff --git a/drivers/gpio/gpiolib-acpi.c b/drivers/gpio/gpiolib-acpi.c
index 55b72fbe1631..bda19373835a 100644
--- a/drivers/gpio/gpiolib-acpi.c
+++ b/drivers/gpio/gpiolib-acpi.c
@@ -22,8 +22,12 @@
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;
It might be a good idea to add kernel-doc now for the struct since it
seems to be growing and it is not immediately clear what each field mean
anymore ;-)
Ok, will do for v2.
struct gpio_desc *desc;
};
@@ -49,10 +53,10 @@ 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 +137,43 @@ 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_request_interrupt_desc(struct acpi_resource *ares,
+ void *context)
I wonder if there could be better name for this now that it does not
request anything? Maybe acpi_gpiochip_event_alloc() or similar?
Sure I will rename this to acpi_gpiochip_alloc_event (verb then subject
to follow the style of the rest of the file) for v2.
I will prepare a v2 of this patch this evening or tomorrow.
Regards,
Hans
