Merge tag 'gpio-v4.19-2' of git://git.kernel.org/pub/scm/linux/kernel/git/linusw/linux-gpio

torvalds · torvalds · commit b36fdc6853a3 · 2018-09-05T09:27:45.000-07:00
Pull GPIO fixes from Linus Walleij:
 "Some GPIO fixes. The ACPI stuff is probably the most annoying for
  users that get fixed this time.

   - Atomic contexts, cansleep* calls and such fastpath/slopwpath
     things.

   - Defer ACPI event handler registration to late_initcall() so IRQs do
     not fire in our face before other drivers have a chance to register
     handlers.

   - Race condition if a consumer requests a GPIO after
     gpiochip_add_data_with_key() but before of_gpiochip_add()

   - Probe errorpath in the dwapb driver"

* tag 'gpio-v4.19-2' of git://git.kernel.org/pub/scm/linux/kernel/git/linusw/linux-gpio:
  gpio: Fix crash due to registration race
  gpio: dwapb: Fix error handling in dwapb_gpio_probe()
  gpiolib-acpi: Register GpioInt ACPI event handlers from a late_initcall
  gpiolib: acpi: Switch to cansleep version of GPIO library call
  gpio: adp5588: Fix sleep-in-atomic-context bug
diff --git a/drivers/gpio/gpio-adp5588.c b/drivers/gpio/gpio-adp5588.c
@@ -41,6 +41,8 @@ struct adp5588_gpio {
 	uint8_t int_en[3];
 	uint8_t irq_mask[3];
 	uint8_t irq_stat[3];
+	uint8_t int_input_en[3];
+	uint8_t int_lvl_cached[3];
 };
 
 static int adp5588_gpio_read(struct i2c_client *client, u8 reg)
@@ -173,12 +175,28 @@ static void adp5588_irq_bus_sync_unlock(struct irq_data *d)
 	struct adp5588_gpio *dev = irq_data_get_irq_chip_data(d);
 	int i;
 
-	for (i = 0; i <= ADP5588_BANK(ADP5588_MAXGPIO); i++)
+	for (i = 0; i <= ADP5588_BANK(ADP5588_MAXGPIO); i++) {
+		if (dev->int_input_en[i]) {
+			mutex_lock(&dev->lock);
+			dev->dir[i] &= ~dev->int_input_en[i];
+			dev->int_input_en[i] = 0;
+			adp5588_gpio_write(dev->client, GPIO_DIR1 + i,
+					   dev->dir[i]);
+			mutex_unlock(&dev->lock);
+		}
+
+		if (dev->int_lvl_cached[i] != dev->int_lvl[i]) {
+			dev->int_lvl_cached[i] = dev->int_lvl[i];
+			adp5588_gpio_write(dev->client, GPIO_INT_LVL1 + i,
+					   dev->int_lvl[i]);
+		}
+
 		if (dev->int_en[i] ^ dev->irq_mask[i]) {
 			dev->int_en[i] = dev->irq_mask[i];
 			adp5588_gpio_write(dev->client, GPIO_INT_EN1 + i,
 					   dev->int_en[i]);
 		}
+	}
 
 	mutex_unlock(&dev->irq_lock);
 }
@@ -221,9 +239,7 @@ static int adp5588_irq_set_type(struct irq_data *d, unsigned int type)
 	else
 		return -EINVAL;
 
-	adp5588_gpio_direction_input(&dev->gpio_chip, gpio);
-	adp5588_gpio_write(dev->client, GPIO_INT_LVL1 + bank,
-			   dev->int_lvl[bank]);
+	dev->int_input_en[bank] |= bit;
 
 	return 0;
 }
diff --git a/drivers/gpio/gpio-dwapb.c b/drivers/gpio/gpio-dwapb.c
@@ -728,6 +728,7 @@ static int dwapb_gpio_probe(struct platform_device *pdev)
 out_unregister:
 	dwapb_gpio_unregister(gpio);
 	dwapb_irq_teardown(gpio);
+	clk_disable_unprepare(gpio->clk);
 
 	return err;
 }
diff --git a/drivers/gpio/gpiolib-acpi.c b/drivers/gpio/gpiolib-acpi.c
@@ -25,7 +25,6 @@
 
 struct acpi_gpio_event {
 	struct list_head node;
-	struct list_head initial_sync_list;
 	acpi_handle handle;
 	unsigned int pin;
 	unsigned int irq;
@@ -49,10 +48,19 @@ struct acpi_gpio_chip {
 	struct mutex conn_lock;
 	struct gpio_chip *chip;
 	struct list_head events;
+	struct list_head deferred_req_irqs_list_entry;
 };
 
-static LIST_HEAD(acpi_gpio_initial_sync_list);
-static DEFINE_MUTEX(acpi_gpio_initial_sync_list_lock);
+/*
+ * For gpiochips which call acpi_gpiochip_request_interrupts() before late_init
+ * (so builtin drivers) we register the ACPI GpioInt event 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.
+ */
+static DEFINE_MUTEX(acpi_gpio_deferred_req_irqs_lock);
+static LIST_HEAD(acpi_gpio_deferred_req_irqs_list);
+static bool acpi_gpio_deferred_req_irqs_done;
 
 static int acpi_gpiochip_find(struct gpio_chip *gc, void *data)
 {
@@ -89,21 +97,6 @@ static struct gpio_desc *acpi_get_gpiod(char *path, int pin)
 	return gpiochip_get_desc(chip, pin);
 }
 
-static void acpi_gpio_add_to_initial_sync_list(struct acpi_gpio_event *event)
-{
-	mutex_lock(&acpi_gpio_initial_sync_list_lock);
-	list_add(&event->initial_sync_list, &acpi_gpio_initial_sync_list);
-	mutex_unlock(&acpi_gpio_initial_sync_list_lock);
-}
-
-static void acpi_gpio_del_from_initial_sync_list(struct acpi_gpio_event *event)
-{
-	mutex_lock(&acpi_gpio_initial_sync_list_lock);
-	if (!list_empty(&event->initial_sync_list))
-		list_del_init(&event->initial_sync_list);
-	mutex_unlock(&acpi_gpio_initial_sync_list_lock);
-}
-
 static irqreturn_t acpi_gpio_irq_handler(int irq, void *data)
 {
 	struct acpi_gpio_event *event = data;
@@ -186,7 +179,7 @@ static acpi_status acpi_gpiochip_request_interrupt(struct acpi_resource *ares,
 
 	gpiod_direction_input(desc);
 
-	value = gpiod_get_value(desc);
+	value = gpiod_get_value_cansleep(desc);
 
 	ret = gpiochip_lock_as_irq(chip, pin);
 	if (ret) {
@@ -229,7 +222,6 @@ static acpi_status acpi_gpiochip_request_interrupt(struct acpi_resource *ares,
 	event->irq = irq;
 	event->pin = pin;
 	event->desc = desc;
-	INIT_LIST_HEAD(&event->initial_sync_list);
 
 	ret = request_threaded_irq(event->irq, NULL, handler, irqflags,
 				   "ACPI:Event", event);
@@ -251,10 +243,9 @@ static acpi_status acpi_gpiochip_request_interrupt(struct acpi_resource *ares,
 	 * may refer to OperationRegions from other (builtin) drivers which
 	 * may be probed after us.
 	 */
-	if (handler == acpi_gpio_irq_handler &&
-	    (((irqflags & IRQF_TRIGGER_RISING) && value == 1) ||
-	     ((irqflags & IRQF_TRIGGER_FALLING) && value == 0)))
-		acpi_gpio_add_to_initial_sync_list(event);
+	if (((irqflags & IRQF_TRIGGER_RISING) && value == 1) ||
+	    ((irqflags & IRQF_TRIGGER_FALLING) && value == 0))
+		handler(event->irq, event);
 
 	return AE_OK;
 
@@ -283,6 +274,7 @@ void acpi_gpiochip_request_interrupts(struct gpio_chip *chip)
 	struct acpi_gpio_chip *acpi_gpio;
 	acpi_handle handle;
 	acpi_status status;
+	bool defer;
 
 	if (!chip->parent || !chip->to_irq)
 		return;
@@ -295,6 +287,16 @@ void acpi_gpiochip_request_interrupts(struct gpio_chip *chip)
 	if (ACPI_FAILURE(status))
 		return;
 
+	mutex_lock(&acpi_gpio_deferred_req_irqs_lock);
+	defer = !acpi_gpio_deferred_req_irqs_done;
+	if (defer)
+		list_add(&acpi_gpio->deferred_req_irqs_list_entry,
+			 &acpi_gpio_deferred_req_irqs_list);
+	mutex_unlock(&acpi_gpio_deferred_req_irqs_lock);
+
+	if (defer)
+		return;
+
 	acpi_walk_resources(handle, "_AEI",
 			    acpi_gpiochip_request_interrupt, acpi_gpio);
 }
@@ -325,11 +327,14 @@ void acpi_gpiochip_free_interrupts(struct gpio_chip *chip)
 	if (ACPI_FAILURE(status))
 		return;
 
+	mutex_lock(&acpi_gpio_deferred_req_irqs_lock);
+	if (!list_empty(&acpi_gpio->deferred_req_irqs_list_entry))
+		list_del_init(&acpi_gpio->deferred_req_irqs_list_entry);
+	mutex_unlock(&acpi_gpio_deferred_req_irqs_lock);
+
 	list_for_each_entry_safe_reverse(event, ep, &acpi_gpio->events, node) {
 		struct gpio_desc *desc;
 
-		acpi_gpio_del_from_initial_sync_list(event);
-
 		if (irqd_is_wakeup_set(irq_get_irq_data(event->irq)))
 			disable_irq_wake(event->irq);
 
@@ -1052,6 +1057,7 @@ void acpi_gpiochip_add(struct gpio_chip *chip)
 
 	acpi_gpio->chip = chip;
 	INIT_LIST_HEAD(&acpi_gpio->events);
+	INIT_LIST_HEAD(&acpi_gpio->deferred_req_irqs_list_entry);
 
 	status = acpi_attach_data(handle, acpi_gpio_chip_dh, acpi_gpio);
 	if (ACPI_FAILURE(status)) {
@@ -1198,20 +1204,28 @@ bool acpi_can_fallback_to_crs(struct acpi_device *adev, const char *con_id)
 	return con_id == NULL;
 }
 
-/* Sync the initial state of handlers after all builtin drivers have probed */
-static int acpi_gpio_initial_sync(void)
+/* Run deferred acpi_gpiochip_request_interrupts() */
+static int acpi_gpio_handle_deferred_request_interrupts(void)
 {
-	struct acpi_gpio_event *event, *ep;
+	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;
 
-	mutex_lock(&acpi_gpio_initial_sync_list_lock);
-	list_for_each_entry_safe(event, ep, &acpi_gpio_initial_sync_list,
-				 initial_sync_list) {
-		acpi_evaluate_object(event->handle, NULL, NULL, NULL);
-		list_del_init(&event->initial_sync_list);
+		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);
 	}
-	mutex_unlock(&acpi_gpio_initial_sync_list_lock);
+
+	acpi_gpio_deferred_req_irqs_done = true;
+	mutex_unlock(&acpi_gpio_deferred_req_irqs_lock);
 
 	return 0;
 }
 /* We must use _sync so that this runs after the first deferred_probe run */
-late_initcall_sync(acpi_gpio_initial_sync);
+late_initcall_sync(acpi_gpio_handle_deferred_request_interrupts);
diff --git a/drivers/gpio/gpiolib-of.c b/drivers/gpio/gpiolib-of.c
@@ -31,6 +31,7 @@ static int of_gpiochip_match_node_and_xlate(struct gpio_chip *chip, void *data)
 	struct of_phandle_args *gpiospec = data;
 
 	return chip->gpiodev->dev.of_node == gpiospec->np &&
+				chip->of_xlate &&
 				chip->of_xlate(chip, gpiospec, NULL) >= 0;
 }
 

Original file line number	Diff line number	Diff line change
`@@ -728,6 +728,7 @@ static int dwapb_gpio_probe(struct platform_device *pdev)`
`728`	`728`	`out_unregister:`
`729`	`729`	`dwapb_gpio_unregister(gpio);`
`730`	`730`	`dwapb_irq_teardown(gpio);`
	`731`	`+ clk_disable_unprepare(gpio->clk);`
`731`	`732`
`732`	`733`	`return err;`
`733`	`734`	`}`
Original file line number	Diff line number	Diff line change
`@@ -31,6 +31,7 @@ static int of_gpiochip_match_node_and_xlate(struct gpio_chip chip, void data)`
`31`	`31`	`struct of_phandle_args *gpiospec = data;`
`32`	`32`
`33`	`33`	`return chip->gpiodev->dev.of_node == gpiospec->np &&`
	`34`	`+ chip->of_xlate &&`
`34`	`35`	`chip->of_xlate(chip, gpiospec, NULL) >= 0;`
`35`	`36`	`}`
`36`	`37`