gpio: dwapb: Call acpi_gpiochip_free_interrupts() on GPIO chip de-registration

Add missed acpi_gpiochip_free_interrupts() call when unregistering ports.

While at it, drop extra check to call acpi_gpiochip_request_interrupts().
There is no need to have an additional check to call
acpi_gpiochip_request_interrupts(). Even without any interrupts available
the registered ACPI Event handlers can be useful for debugging purposes.

Fixes: e6cb3486 ("gpio: dwapb: add gpio-signaled acpi event support")
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Tested-by: Serge Semin <fancer.lancer@gmail.com>
Acked-by: Serge Semin <fancer.lancer@gmail.com>
Link: https://lore.kernel.org/r/20200519131233.59032-1-andriy.shevchenko@linux.intel.comSigned-off-by: Linus Walleij <linus.walleij@linaro.org>

drivers/gpio/gpio-dwapb.c

@@ -505,26 +505,33 @@ static int dwapb_gpio_add_port(struct dwapb_gpio *gpio,
 		dwapb_configure_irqs(gpio, port, pp);
 
 	err = gpiochip_add_data(&port->gc, port);
-	if (err)
+	if (err) {
 		dev_err(gpio->dev, "failed to register gpiochip for port%d\n",
 			port->idx);
-	else
-		port->is_registered = true;
+		return err;
+	}
 
 	/* Add GPIO-signaled ACPI event support */
-	if (pp->has_irq)
-		acpi_gpiochip_request_interrupts(&port->gc);
+	acpi_gpiochip_request_interrupts(&port->gc);
 
-	return err;
+	port->is_registered = true;
+
+	return 0;
 }
 
 static void dwapb_gpio_unregister(struct dwapb_gpio *gpio)
 {
 	unsigned int m;
 
-	for (m = 0; m < gpio->nr_ports; ++m)
-		if (gpio->ports[m].is_registered)
-			gpiochip_remove(&gpio->ports[m].gc);
+	for (m = 0; m < gpio->nr_ports; ++m) {
+		struct dwapb_gpio_port *port = &gpio->ports[m];
+
+		if (!port->is_registered)
+			continue;
+
+		acpi_gpiochip_free_interrupts(&port->gc);
+		gpiochip_remove(&port->gc);
+	}
 }
 
 static void dwapb_get_irq(struct device *dev, struct fwnode_handle *fwnode,