On Tue, Dec 13, 2016 at 11:55:02PM -0800, Jaghathiswari Rankappagounder Natarajan wrote: > +int seven_seg_setup_cdev(struct seven_seg_disp_dev *disp_dev, > + void (*update_disp_data)(struct device *, u16 data)) > +{ > + struct device *dev; > + int err; > + > + dev = device_create(seven_seg_disp_class, &disp_dev->parent, > + seven_seg_devno, > + NULL, "seven_seg_disp_val"); > + if (dev == NULL) > + return -1; Do not use return -1 in kernel code. > + disp_dev->dev = dev; > + disp_dev->update_seven_seg_data = update_disp_data; > + disp_dev->disp_data_valid = false; > + > + cdev_init(&disp_dev->cdev, &seven_seg_disp_fops); > + err = cdev_add(&disp_dev->cdev, seven_seg_devno, 1); > + if (err) > + device_destroy(seven_seg_disp_class, seven_seg_devno); > + return err; > +} > + > +static int __init seven_seg_disp_init(void) > +{ > + if (alloc_chrdev_region(&seven_seg_devno, 0, 1, "disp_state") < 0) > + return -1; Do not use return -1 in kernel code. > + > + seven_seg_disp_class = class_create(THIS_MODULE, "disp_state"); > + if (seven_seg_disp_class == NULL) > + goto unreg_chrdev; > + > +unreg_chrdev: > + unregister_chrdev_region(seven_seg_devno, 1); > + return -1; Do not use return -1 in kernel code. (Look up what an errno value of '1' means. Negative values returned from functions are interpreted as negated errno values.) Always propagate error codes, or select an appropriate errno value to return. -- RMK's Patch system: http://www.armlinux.org.uk/developer/patches/ FTTC broadband for 0.8mile line: currently at 9.6Mbps down 400kbps up according to speedtest.net. -- To unsubscribe from this list: send the line "unsubscribe devicetree" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html