[media] lirc_imon: simplify error handling code

Instead of using a state machine and a switch with lots of
fall-trough, use gotos and cleanup the error handling loop.

That removes those two smatch warnings:
	drivers/staging/media/lirc/lirc_imon.c:933 imon_probe() warn: possible memory leak of 'context'
	drivers/staging/media/lirc/lirc_imon.c:933 imon_probe() warn: possible memory leak of 'driver'

And make the error handling code more standard.

Signed-off-by: Mauro Carvalho Chehab <mchehab@osg.samsung.com>

diff --git a/drivers/staging/media/lirc/lirc_imon.c b/drivers/staging/media/lirc/lirc_imon.c
index 335b98a..62ec9f7 100644 (file)
--- a/drivers/staging/media/lirc/lirc_imon.c
+++ b/drivers/staging/media/lirc/lirc_imon.c
@@ -693,10 +693,9 @@ static int imon_probe(struct usb_interface *interface,
        int ifnum;
        int lirc_minor = 0;
        int num_endpts;
-       int retval = 0;
+       int retval = -ENOMEM;
        int display_ep_found = 0;
        int ir_ep_found = 0;
-       int alloc_status = 0;
        int vfd_proto_6p = 0;
        struct imon_context *context = NULL;
        int i;
@@ -706,10 +705,8 @@ static int imon_probe(struct usb_interface *interface,
        mutex_lock(&driver_lock);
 
        context = kzalloc(sizeof(struct imon_context), GFP_KERNEL);
-       if (!context) {
-               alloc_status = 1;
-               goto alloc_status_switch;
-       }
+       if (!context)
+               goto driver_unlock;
 
        /*
         * Try to auto-detect the type of display if the user hasn't set
@@ -775,8 +772,7 @@ static int imon_probe(struct usb_interface *interface,
                dev_err(dev, "%s: no valid input (IR) endpoint found.\n",
                        __func__);
                retval = -ENODEV;
-               alloc_status = 2;
-               goto alloc_status_switch;
+               goto free_context;
        }
 
        /* Determine if display requires 6 packets */
@@ -790,31 +786,26 @@ static int imon_probe(struct usb_interface *interface,
 
        driver = kzalloc(sizeof(struct lirc_driver), GFP_KERNEL);
        if (!driver) {
-               alloc_status = 2;
-               goto alloc_status_switch;
+               goto free_context;
        }
        rbuf = kmalloc(sizeof(struct lirc_buffer), GFP_KERNEL);
        if (!rbuf) {
-               alloc_status = 3;
-               goto alloc_status_switch;
+               goto free_driver;
        }
        if (lirc_buffer_init(rbuf, BUF_CHUNK_SIZE, BUF_SIZE)) {
                dev_err(dev, "%s: lirc_buffer_init failed\n", __func__);
-               alloc_status = 4;
-               goto alloc_status_switch;
+               goto free_rbuf;
        }
        rx_urb = usb_alloc_urb(0, GFP_KERNEL);
        if (!rx_urb) {
                dev_err(dev, "%s: usb_alloc_urb failed for IR urb\n", __func__);
-               alloc_status = 5;
-               goto alloc_status_switch;
+               goto free_lirc_buf;
        }
        tx_urb = usb_alloc_urb(0, GFP_KERNEL);
        if (!tx_urb) {
                dev_err(dev, "%s: usb_alloc_urb failed for display urb\n",
                    __func__);
-               alloc_status = 6;
-               goto alloc_status_switch;
+               goto free_rx_urb;
        }
 
        mutex_init(&context->ctx_lock);
@@ -840,11 +831,11 @@ static int imon_probe(struct usb_interface *interface,
        lirc_minor = lirc_register_driver(driver);
        if (lirc_minor < 0) {
                dev_err(dev, "%s: lirc_register_driver failed\n", __func__);
-               alloc_status = 7;
-               goto unlock;
-       } else
-               dev_info(dev, "Registered iMON driver (lirc minor: %d)\n",
-                        lirc_minor);
+               goto free_tx_urb;
+       }
+
+       dev_info(dev, "Registered iMON driver (lirc minor: %d)\n",
+                       lirc_minor);
 
        /* Needed while unregistering! */
        driver->minor = lirc_minor;
@@ -872,11 +863,9 @@ static int imon_probe(struct usb_interface *interface,
                context->rx_endpoint->bInterval);
 
        retval = usb_submit_urb(context->rx_urb, GFP_KERNEL);
-
        if (retval) {
                dev_err(dev, "usb_submit_urb failed for intf0 (%d)\n", retval);
-               alloc_status = 8;
-               goto unlock;
+               goto unregister_lirc;
        }
 
        usb_set_intfdata(interface, context);
@@ -895,39 +884,31 @@ static int imon_probe(struct usb_interface *interface,
        dev_info(dev, "iMON device (%04x:%04x, intf%d) on usb<%d:%d> initialized\n",
                vendor, product, ifnum, usbdev->bus->busnum, usbdev->devnum);
 
-unlock:
-       mutex_unlock(&context->ctx_lock);
-alloc_status_switch:
-
-       switch (alloc_status) {
-       case 8:
-               lirc_unregister_driver(driver->minor);
-       case 7:
-               usb_free_urb(tx_urb);
-       case 6:
-               usb_free_urb(rx_urb);
-               /* fall-through */
-       case 5:
-               if (rbuf)
-                       lirc_buffer_free(rbuf);
-               /* fall-through */
-       case 4:
-               kfree(rbuf);
-               /* fall-through */
-       case 3:
-               kfree(driver);
-               /* fall-through */
-       case 2:
-               kfree(context);
-               context = NULL;
-       case 1:
-               if (retval != -ENODEV)
-                       retval = -ENOMEM;
-               break;
-       case 0:
-               retval = 0;
-       }
+       /* Everything went fine. Just unlock and return retval (with is 0) */
+       goto driver_unlock;
+
+unregister_lirc:
+       lirc_unregister_driver(driver->minor);
+
+free_tx_urb:
+       usb_free_urb(tx_urb);
+
+free_rx_urb:
+       usb_free_urb(rx_urb);
+
+free_lirc_buf:
+       lirc_buffer_free(rbuf);
+
+free_rbuf:
+       kfree(rbuf);
+
+free_driver:
+       kfree(driver);
+free_context:
+       kfree(context);
+       context = NULL;
 
+driver_unlock:
        mutex_unlock(&driver_lock);
 
        return retval;