gpio: pcf857x: Check for irq_set_irq_wake() failures

If an interrupt controller doesn't support wake-up configuration,
irq_set_irq_wake() returns an error code.  Then any subsequent call
trying to deconfigure wake-up will cause an imbalance, and a warning
will be printed:

    WARNING: CPU: 1 PID: 1341 at kernel/irq/manage.c:540 irq_set_irq_wake+0x
    Unbalanced IRQ 26 wake disable

To fix this, refrain from any further parent interrupt controller
(de)configuration if irq_set_irq_wake() failed.

Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>

1 files changed, 14 insertions, 2 deletions

diff --git a/drivers/gpio/gpio-pcf857x.c b/drivers/gpio/gpio-pcf857x.c
index 945f0cda8529..83db0e19ec7e 100644
--- a/drivers/gpio/gpio-pcf857x.c
+++ b/drivers/gpio/gpio-pcf857x.c
@@ -91,6 +91,7 @@ struct pcf857x {
         spinlock_t              slock;          /* protect irq demux */
         unsigned                out;            /* software latch */
         unsigned                status;         /* current status */
+        unsigned int            irq_parent;
 
         int (*write)(struct i2c_client *client, unsigned data);
         int (*read)(struct i2c_client *client);
@@ -217,9 +218,19 @@ static unsigned int noop_ret(struct irq_data *data)
 static int pcf857x_irq_set_wake(struct irq_data *data, unsigned int on)
 {
         struct pcf857x *gpio = irq_data_get_irq_chip_data(data);
+        int error = 0;
+
+        if (gpio->irq_parent) {
+                error = irq_set_irq_wake(gpio->irq_parent, on);
+                if (error) {
+                        dev_dbg(&gpio->client->dev,
+                                "irq %u doesn't support irq_set_wake\n",
+                                gpio->irq_parent);
+                        gpio->irq_parent = 0;
+                }
+        }
 
-        irq_set_irq_wake(gpio->client->irq, on);
-        return 0;
+        return error;
 }
 
 static struct irq_chip pcf857x_irq_chip = {
@@ -364,6 +375,7 @@ static int pcf857x_probe(struct i2c_client *client,
 
                 gpiochip_set_chained_irqchip(&gpio->chip, &pcf857x_irq_chip,
                                              client->irq, NULL);
+                gpio->irq_parent = client->irq;
         }
 
         /* Let platform code set up the GPIOs and their users.