[PATCH] USB: core: Improve unlocking of a mutex in two functions

[SF Markus Elfring]

From: Markus Elfring <elfr...@users.sourceforge.net>
Date: Sat, 4 Nov 2017 21:00:46 +0100

* Add jump targets so that a call of the function "mutex_unlock" is stored
  only twice in these function implementations.

* Replace five calls by goto statements.

This issue was detected by using the Coccinelle software.

Signed-off-by: Markus Elfring <elfr...@users.sourceforge.net>
---
 drivers/usb/core/hub.c     |  8 ++++----
 drivers/usb/core/message.c | 18 ++++++++++--------
 2 files changed, 14 insertions(+), 12 deletions(-)

diff --git a/drivers/usb/core/hub.c b/drivers/usb/core/hub.c
index 196a0a5540ed..8f3067c2015c 100644
--- a/drivers/usb/core/hub.c
+++ b/drivers/usb/core/hub.c
@@ -5518,8 +5518,7 @@ static int usb_reset_and_verify_device(struct usb_device 
*udev)
                dev_warn(&udev->dev,
                                "Busted HC?  Not enough HCD resources for "
                                "old configuration.\n");
-               mutex_unlock(hcd->bandwidth_mutex);
-               goto re_enumerate;
+               goto unlock;
        }
        ret = usb_control_msg(udev, usb_sndctrlpipe(udev, 0),
                        USB_REQ_SET_CONFIGURATION, 0,
@@ -5529,8 +5528,7 @@ static int usb_reset_and_verify_device(struct usb_device 
*udev)
                dev_err(&udev->dev,
                        "can't restore configuration #%d (error=%d)\n",
                        udev->actconfig->desc.bConfigurationValue, ret);
-               mutex_unlock(hcd->bandwidth_mutex);
-               goto re_enumerate;
+               goto unlock;
        }
        mutex_unlock(hcd->bandwidth_mutex);
        usb_set_device_state(udev, USB_STATE_CONFIGURED);
@@ -5583,6 +5581,8 @@ static int usb_reset_and_verify_device(struct usb_device 
*udev)
        udev->bos = bos;
        return 0;
 
+unlock:
+       mutex_unlock(hcd->bandwidth_mutex);
 re_enumerate:
        usb_release_bos_descriptor(udev);
        udev->bos = bos;
diff --git a/drivers/usb/core/message.c b/drivers/usb/core/message.c
index 371a07d874a3..fe8e36cc7def 100644
--- a/drivers/usb/core/message.c
+++ b/drivers/usb/core/message.c
@@ -1321,8 +1321,8 @@ int usb_set_interface(struct usb_device *dev, int 
interface, int alternate)
         */
        if (usb_disable_lpm(dev)) {
                dev_err(&iface->dev, "%s Failed to disable LPM\n.", __func__);
-               mutex_unlock(hcd->bandwidth_mutex);
-               return -ENOMEM;
+               ret = -ENOMEM;
+               goto unlock;
        }
        /* Changing alt-setting also frees any allocated streams */
        for (i = 0; i < iface->cur_altsetting->desc.bNumEndpoints; i++)
@@ -1332,9 +1332,7 @@ int usb_set_interface(struct usb_device *dev, int 
interface, int alternate)
        if (ret < 0) {
                dev_info(&dev->dev, "Not enough bandwidth for altsetting %d\n",
                                alternate);
-               usb_enable_lpm(dev);
-               mutex_unlock(hcd->bandwidth_mutex);
-               return ret;
+               goto enable_lpm;
        }
 
        if (dev->quirks & USB_QUIRK_NO_SET_INTF)
@@ -1355,9 +1353,7 @@ int usb_set_interface(struct usb_device *dev, int 
interface, int alternate)
        } else if (ret < 0) {
                /* Re-instate the old alt setting */
                usb_hcd_alloc_bandwidth(dev, NULL, alt, iface->cur_altsetting);
-               usb_enable_lpm(dev);
-               mutex_unlock(hcd->bandwidth_mutex);
-               return ret;
+               goto enable_lpm;
        }
        mutex_unlock(hcd->bandwidth_mutex);
 
@@ -1413,6 +1409,12 @@ int usb_set_interface(struct usb_device *dev, int 
interface, int alternate)
                create_intf_ep_devs(iface);
        }
        return 0;
+
+enable_lpm:
+       usb_enable_lpm(dev);
+unlock:
+       mutex_unlock(hcd->bandwidth_mutex);
+       return ret;
 }
 EXPORT_SYMBOL_GPL(usb_set_interface);
 
-- 
2.15.0