Input: xpad - use guard notation when acquiring mutex and spinlock

Using guard notation 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.

Link: https://lore.kernel.org/r/20240904043104.1030257-7-dmitry.torokhov@gmail.com
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>

diff --git a/drivers/input/joystick/xpad.c b/drivers/input/joystick/xpad.c
index 4eda18f..3e61df9 100644 (file)
--- a/drivers/input/joystick/xpad.c
+++ b/drivers/input/joystick/xpad.c
@@ -1289,9 +1289,8 @@ static void xpad_irq_out(struct urb *urb)
        struct device *dev = &xpad->intf->dev;
        int status = urb->status;
        int error;
-       unsigned long flags;
 
-       spin_lock_irqsave(&xpad->odata_lock, flags);
+       guard(spinlock_irqsave)(&xpad->odata_lock);
 
        switch (status) {
        case 0:
@@ -1325,8 +1324,6 @@ static void xpad_irq_out(struct urb *urb)
                        xpad->irq_out_active = false;
                }
        }
-
-       spin_unlock_irqrestore(&xpad->odata_lock, flags);
 }
 
 static int xpad_init_output(struct usb_interface *intf, struct usb_xpad *xpad,
@@ -1391,10 +1388,8 @@ static int xpad_inquiry_pad_presence(struct usb_xpad *xpad)
 {
        struct xpad_output_packet *packet =
                        &xpad->out_packets[XPAD_OUT_CMD_IDX];
-       unsigned long flags;
-       int retval;
 
-       spin_lock_irqsave(&xpad->odata_lock, flags);
+       guard(spinlock_irqsave)(&xpad->odata_lock);
 
        packet->data[0] = 0x08;
        packet->data[1] = 0x00;
@@ -1413,17 +1408,12 @@ static int xpad_inquiry_pad_presence(struct usb_xpad *xpad)
 
        /* Reset the sequence so we send out presence first */
        xpad->last_out_packet = -1;
-       retval = xpad_try_sending_next_out_packet(xpad);
-
-       spin_unlock_irqrestore(&xpad->odata_lock, flags);
-
-       return retval;
+       return xpad_try_sending_next_out_packet(xpad);
 }
 
 static int xpad_start_xbox_one(struct usb_xpad *xpad)
 {
-       unsigned long flags;
-       int retval;
+       int error;
 
        if (usb_ifnum_to_if(xpad->udev, GIP_WIRED_INTF_AUDIO)) {
                /*
@@ -1432,15 +1422,15 @@ static int xpad_start_xbox_one(struct usb_xpad *xpad)
                 * Controller for Series X|S (0x20d6:0x200e) to report the
                 * guide button.
                 */
-               retval = usb_set_interface(xpad->udev,
-                                          GIP_WIRED_INTF_AUDIO, 0);
-               if (retval)
+               error = usb_set_interface(xpad->udev,
+                                         GIP_WIRED_INTF_AUDIO, 0);
+               if (error)
                        dev_warn(&xpad->dev->dev,
                                 "unable to disable audio interface: %d\n",
-                                retval);
+                                error);
        }
 
-       spin_lock_irqsave(&xpad->odata_lock, flags);
+       guard(spinlock_irqsave)(&xpad->odata_lock);
 
        /*
         * Begin the init sequence by attempting to send a packet.
@@ -1448,16 +1438,11 @@ static int xpad_start_xbox_one(struct usb_xpad *xpad)
         * sending any packets from the output ring.
         */
        xpad->init_seq = 0;
-       retval = xpad_try_sending_next_out_packet(xpad);
-
-       spin_unlock_irqrestore(&xpad->odata_lock, flags);
-
-       return retval;
+       return xpad_try_sending_next_out_packet(xpad);
 }
 
 static void xpadone_ack_mode_report(struct usb_xpad *xpad, u8 seq_num)
 {
-       unsigned long flags;
        struct xpad_output_packet *packet =
                        &xpad->out_packets[XPAD_OUT_CMD_IDX];
        static const u8 mode_report_ack[] = {
@@ -1465,7 +1450,7 @@ static void xpadone_ack_mode_report(struct usb_xpad *xpad, u8 seq_num)
                0x00, GIP_CMD_VIRTUAL_KEY, GIP_OPT_INTERNAL, 0x02, 0x00, 0x00, 0x00, 0x00, 0x00
        };
 
-       spin_lock_irqsave(&xpad->odata_lock, flags);
+       guard(spinlock_irqsave)(&xpad->odata_lock);
 
        packet->len = sizeof(mode_report_ack);
        memcpy(packet->data, mode_report_ack, packet->len);
@@ -1475,8 +1460,6 @@ static void xpadone_ack_mode_report(struct usb_xpad *xpad, u8 seq_num)
        /* Reset the sequence so we send out the ack now */
        xpad->last_out_packet = -1;
        xpad_try_sending_next_out_packet(xpad);
-
-       spin_unlock_irqrestore(&xpad->odata_lock, flags);
 }
 
 #ifdef CONFIG_JOYSTICK_XPAD_FF
@@ -1486,8 +1469,6 @@ static int xpad_play_effect(struct input_dev *dev, void *data, struct ff_effect
        struct xpad_output_packet *packet = &xpad->out_packets[XPAD_OUT_FF_IDX];
        __u16 strong;
        __u16 weak;
-       int retval;
-       unsigned long flags;
 
        if (effect->type != FF_RUMBLE)
                return 0;
@@ -1495,7 +1476,7 @@ static int xpad_play_effect(struct input_dev *dev, void *data, struct ff_effect
        strong = effect->u.rumble.strong_magnitude;
        weak = effect->u.rumble.weak_magnitude;
 
-       spin_lock_irqsave(&xpad->odata_lock, flags);
+       guard(spinlock_irqsave)(&xpad->odata_lock);
 
        switch (xpad->xtype) {
        case XTYPE_XBOX:
@@ -1561,15 +1542,10 @@ static int xpad_play_effect(struct input_dev *dev, void *data, struct ff_effect
                dev_dbg(&xpad->dev->dev,
                        "%s - rumble command sent to unsupported xpad type: %d\n",
                        __func__, xpad->xtype);
-               retval = -EINVAL;
-               goto out;
+               return -EINVAL;
        }
 
-       retval = xpad_try_sending_next_out_packet(xpad);
-
-out:
-       spin_unlock_irqrestore(&xpad->odata_lock, flags);
-       return retval;
+       return xpad_try_sending_next_out_packet(xpad);
 }
 
 static int xpad_init_ff(struct usb_xpad *xpad)
@@ -1622,11 +1598,10 @@ static void xpad_send_led_command(struct usb_xpad *xpad, int command)
 {
        struct xpad_output_packet *packet =
                        &xpad->out_packets[XPAD_OUT_LED_IDX];
-       unsigned long flags;
 
        command %= 16;
 
-       spin_lock_irqsave(&xpad->odata_lock, flags);
+       guard(spinlock_irqsave)(&xpad->odata_lock);
 
        switch (xpad->xtype) {
        case XTYPE_XBOX360:
@@ -1656,8 +1631,6 @@ static void xpad_send_led_command(struct usb_xpad *xpad, int command)
        }
 
        xpad_try_sending_next_out_packet(xpad);
-
-       spin_unlock_irqrestore(&xpad->odata_lock, flags);
 }
 
 /*
@@ -1782,11 +1755,10 @@ static void xpad_stop_input(struct usb_xpad *xpad)
 
 static void xpad360w_poweroff_controller(struct usb_xpad *xpad)
 {
-       unsigned long flags;
        struct xpad_output_packet *packet =
                        &xpad->out_packets[XPAD_OUT_CMD_IDX];
 
-       spin_lock_irqsave(&xpad->odata_lock, flags);
+       guard(spinlock_irqsave)(&xpad->odata_lock);
 
        packet->data[0] = 0x00;
        packet->data[1] = 0x00;
@@ -1806,8 +1778,6 @@ static void xpad360w_poweroff_controller(struct usb_xpad *xpad)
        /* Reset the sequence so we send out poweroff now */
        xpad->last_out_packet = -1;
        xpad_try_sending_next_out_packet(xpad);
-
-       spin_unlock_irqrestore(&xpad->odata_lock, flags);
 }
 
 static int xpad360w_start_input(struct usb_xpad *xpad)
@@ -2231,10 +2201,10 @@ static int xpad_suspend(struct usb_interface *intf, pm_message_t message)
                if (auto_poweroff && xpad->pad_present)
                        xpad360w_poweroff_controller(xpad);
        } else {
-               mutex_lock(&input->mutex);
+               guard(mutex)(&input->mutex);
+
                if (input_device_enabled(input))
                        xpad_stop_input(xpad);
-               mutex_unlock(&input->mutex);
        }
 
        xpad_stop_output(xpad);
@@ -2246,26 +2216,25 @@ static int xpad_resume(struct usb_interface *intf)
 {
        struct usb_xpad *xpad = usb_get_intfdata(intf);
        struct input_dev *input = xpad->dev;
-       int retval = 0;
 
-       if (xpad->xtype == XTYPE_XBOX360W) {
-               retval = xpad360w_start_input(xpad);
-       } else {
-               mutex_lock(&input->mutex);
-               if (input_device_enabled(input)) {
-                       retval = xpad_start_input(xpad);
-               } else if (xpad->xtype == XTYPE_XBOXONE) {
-                       /*
-                        * Even if there are no users, we'll send Xbox One pads
-                        * the startup sequence so they don't sit there and
-                        * blink until somebody opens the input device again.
-                        */
-                       retval = xpad_start_xbox_one(xpad);
-               }
-               mutex_unlock(&input->mutex);
+       if (xpad->xtype == XTYPE_XBOX360W)
+               return xpad360w_start_input(xpad);
+
+       guard(mutex)(&input->mutex);
+
+       if (input_device_enabled(input))
+               return xpad_start_input(xpad);
+
+       if (xpad->xtype == XTYPE_XBOXONE) {
+               /*
+                * Even if there are no users, we'll send Xbox One pads
+                * the startup sequence so they don't sit there and
+                * blink until somebody opens the input device again.
+                */
+               return xpad_start_xbox_one(xpad);
        }
 
-       return retval;
+       return 0;
 }
 
 static struct usb_driver xpad_driver = {