[PATCH 02/17] Input: applespi - use guard notation when acquiring spinlock

[Dmitry Torokhov <dmitry.torokhov@gmail.com>]

This makes the code more compact and error handling more robust
by ensuring that locks are released in all code paths when control
leaves critical section.

Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
---
 drivers/input/keyboard/applespi.c | 72 ++++++++-----------------------
 1 file changed, 18 insertions(+), 54 deletions(-)

diff --git a/drivers/input/keyboard/applespi.c b/drivers/input/keyboard/applespi.c
index cf25177b4830..501ce8154786 100644
--- a/drivers/input/keyboard/applespi.c
+++ b/drivers/input/keyboard/applespi.c
@@ -717,9 +717,7 @@ static int applespi_send_cmd_msg(struct applespi_data *applespi);
 static void applespi_msg_complete(struct applespi_data *applespi,
 				  bool is_write_msg, bool is_read_compl)
 {
-	unsigned long flags;
-
-	spin_lock_irqsave(&applespi->cmd_msg_lock, flags);
+	guard(spinlock_irqsave)(&applespi->cmd_msg_lock);
 
 	if (is_read_compl)
 		applespi->read_active = false;
@@ -733,8 +731,6 @@ static void applespi_msg_complete(struct applespi_data *applespi,
 		applespi->cmd_msg_queued = 0;
 		applespi_send_cmd_msg(applespi);
 	}
-
-	spin_unlock_irqrestore(&applespi->cmd_msg_lock, flags);
 }
 
 static void applespi_async_write_complete(void *context)
@@ -888,33 +884,22 @@ static int applespi_send_cmd_msg(struct applespi_data *applespi)
 
 static void applespi_init(struct applespi_data *applespi, bool is_resume)
 {
-	unsigned long flags;
-
-	spin_lock_irqsave(&applespi->cmd_msg_lock, flags);
+	guard(spinlock_irqsave)(&applespi->cmd_msg_lock);
 
 	if (is_resume)
 		applespi->want_mt_init_cmd = true;
 	else
 		applespi->want_tp_info_cmd = true;
 	applespi_send_cmd_msg(applespi);
-
-	spin_unlock_irqrestore(&applespi->cmd_msg_lock, flags);
 }
 
 static int applespi_set_capsl_led(struct applespi_data *applespi,
 				  bool capslock_on)
 {
-	unsigned long flags;
-	int sts;
-
-	spin_lock_irqsave(&applespi->cmd_msg_lock, flags);
+	guard(spinlock_irqsave)(&applespi->cmd_msg_lock);
 
 	applespi->want_cl_led_on = capslock_on;
-	sts = applespi_send_cmd_msg(applespi);
-
-	spin_unlock_irqrestore(&applespi->cmd_msg_lock, flags);
-
-	return sts;
+	return applespi_send_cmd_msg(applespi);
 }
 
 static void applespi_set_bl_level(struct led_classdev *led_cdev,
@@ -922,9 +907,8 @@ static void applespi_set_bl_level(struct led_classdev *led_cdev,
 {
 	struct applespi_data *applespi =
 		container_of(led_cdev, struct applespi_data, backlight_info);
-	unsigned long flags;
 
-	spin_lock_irqsave(&applespi->cmd_msg_lock, flags);
+	guard(spinlock_irqsave)(&applespi->cmd_msg_lock);
 
 	if (value == 0) {
 		applespi->want_bl_level = value;
@@ -940,8 +924,6 @@ static void applespi_set_bl_level(struct led_classdev *led_cdev,
 	}
 
 	applespi_send_cmd_msg(applespi);
-
-	spin_unlock_irqrestore(&applespi->cmd_msg_lock, flags);
 }
 
 static int applespi_event(struct input_dev *dev, unsigned int type,
@@ -1428,9 +1410,7 @@ static void applespi_got_data(struct applespi_data *applespi)
 	/* process packet header */
 	if (!applespi_verify_crc(applespi, applespi->rx_buffer,
 				 APPLESPI_PACKET_SIZE)) {
-		unsigned long flags;
-
-		spin_lock_irqsave(&applespi->cmd_msg_lock, flags);
+		guard(spinlock_irqsave)(&applespi->cmd_msg_lock);
 
 		if (applespi->drain) {
 			applespi->read_active = false;
@@ -1439,8 +1419,6 @@ static void applespi_got_data(struct applespi_data *applespi)
 			wake_up_all(&applespi->drain_complete);
 		}
 
-		spin_unlock_irqrestore(&applespi->cmd_msg_lock, flags);
-
 		return;
 	}
 
@@ -1573,11 +1551,10 @@ static u32 applespi_notify(acpi_handle gpe_device, u32 gpe, void *context)
 {
 	struct applespi_data *applespi = context;
 	int sts;
-	unsigned long flags;
 
 	trace_applespi_irq_received(ET_RD_IRQ, PT_READ);
 
-	spin_lock_irqsave(&applespi->cmd_msg_lock, flags);
+	guard(spinlock_irqsave)(&applespi->cmd_msg_lock);
 
 	if (!applespi->suspended) {
 		sts = applespi_async(applespi, &applespi->rd_m,
@@ -1590,8 +1567,6 @@ static u32 applespi_notify(acpi_handle gpe_device, u32 gpe, void *context)
 			applespi->read_active = true;
 	}
 
-	spin_unlock_irqrestore(&applespi->cmd_msg_lock, flags);
-
 	return ACPI_INTERRUPT_HANDLED;
 }
 
@@ -1819,29 +1794,21 @@ static int applespi_probe(struct spi_device *spi)
 
 static void applespi_drain_writes(struct applespi_data *applespi)
 {
-	unsigned long flags;
-
-	spin_lock_irqsave(&applespi->cmd_msg_lock, flags);
+	guard(spinlock_irqsave)(&applespi->cmd_msg_lock);
 
 	applespi->drain = true;
 	wait_event_lock_irq(applespi->drain_complete, !applespi->write_active,
 			    applespi->cmd_msg_lock);
-
-	spin_unlock_irqrestore(&applespi->cmd_msg_lock, flags);
 }
 
 static void applespi_drain_reads(struct applespi_data *applespi)
 {
-	unsigned long flags;
-
-	spin_lock_irqsave(&applespi->cmd_msg_lock, flags);
+	guard(spinlock_irqsave)(&applespi->cmd_msg_lock);
 
 	wait_event_lock_irq(applespi->drain_complete, !applespi->read_active,
 			    applespi->cmd_msg_lock);
 
 	applespi->suspended = true;
-
-	spin_unlock_irqrestore(&applespi->cmd_msg_lock, flags);
 }
 
 static void applespi_remove(struct spi_device *spi)
@@ -1908,21 +1875,18 @@ static int applespi_resume(struct device *dev)
 	struct spi_device *spi = to_spi_device(dev);
 	struct applespi_data *applespi = spi_get_drvdata(spi);
 	acpi_status acpi_sts;
-	unsigned long flags;
 
 	/* ensure our flags and state reflect a newly resumed device */
-	spin_lock_irqsave(&applespi->cmd_msg_lock, flags);
-
-	applespi->drain = false;
-	applespi->have_cl_led_on = false;
-	applespi->have_bl_level = 0;
-	applespi->cmd_msg_queued = 0;
-	applespi->read_active = false;
-	applespi->write_active = false;
-
-	applespi->suspended = false;
+	scoped_guard(spinlock_irqsave, &applespi->cmd_msg_lock) {
+		applespi->drain = false;
+		applespi->have_cl_led_on = false;
+		applespi->have_bl_level = 0;
+		applespi->cmd_msg_queued = 0;
+		applespi->read_active = false;
+		applespi->write_active = false;
 
-	spin_unlock_irqrestore(&applespi->cmd_msg_lock, flags);
+		applespi->suspended = false;
+	}
 
 	/* switch on the SPI interface */
 	applespi_enable_spi(applespi);
-- 
2.46.0.295.g3b9ea8a38a-goog