can: gs_usb: gs_make_candev(): clean up error handling

Introduce a label to free the allocated candev in case of an error and
make use of if. Fix a memory leak if the extended bit timing cannot be
read. Extend the error messages to print the number of the failing
channel and the symbolic error name.

Link: https://lore.kernel.org/all/20220921193902.575416-4-mkl@pengutronix.de
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>

diff --git a/drivers/net/can/usb/gs_usb.c b/drivers/net/can/usb/gs_usb.c
index 28a6454..e9b07e5 100644 (file)
--- a/drivers/net/can/usb/gs_usb.c
+++ b/drivers/net/can/usb/gs_usb.c
@@ -1100,8 +1100,8 @@ static struct gs_can *gs_make_candev(unsigned int channel,
 
        if (rc) {
                dev_err(&intf->dev,
-                       "Couldn't get bit timing const for channel (err=%d)\n",
-                       rc);
+                       "Couldn't get bit timing const for channel %d (%pe)\n",
+                       channel, ERR_PTR(rc));
                return ERR_PTR(rc);
        }
 
@@ -1215,9 +1215,9 @@ static struct gs_can *gs_make_candev(unsigned int channel,
                                          1000, GFP_KERNEL);
                if (rc) {
                        dev_err(&intf->dev,
-                               "Couldn't get extended bit timing const for channel (err=%d)\n",
-                               rc);
-                       return ERR_PTR(rc);
+                               "Couldn't get extended bit timing const for channel %d (%pe)\n",
+                               channel, ERR_PTR(rc));
+                       goto out_free_candev;
                }
 
                strcpy(dev->data_bt_const.name, KBUILD_MODNAME);
@@ -1237,12 +1237,17 @@ static struct gs_can *gs_make_candev(unsigned int channel,
 
        rc = register_candev(dev->netdev);
        if (rc) {
-               free_candev(dev->netdev);
-               dev_err(&intf->dev, "Couldn't register candev (err=%d)\n", rc);
-               return ERR_PTR(rc);
+               dev_err(&intf->dev,
+                       "Couldn't register candev for channel %d (%pe)\n",
+                       channel, ERR_PTR(rc));
+               goto out_free_candev;
        }
 
        return dev;
+
+ out_free_candev:
+       free_candev(dev->netdev);
+       return ERR_PTR(rc);
 }
 
 static void gs_destroy_candev(struct gs_can *dev)