On Sat, Jul 29, 2017 at 04:18:03PM +0800, Lu Baolu wrote: > +static void xhci_debugfs_create_files(struct xhci_hcd *xhci, > + struct xhci_file_map *files, > + size_t nentries, void *data, > + struct dentry *parent, > + const struct file_operations *fops) > +{ > + int i; > + struct dentry *file; > + > + for (i = 0; i < nentries; i++) { > + file = debugfs_create_file(files[i].name, 0444, > + parent, data, fops); > + if (IS_ERR_OR_NULL(file)) > + break; There's no need to ever check the return value of a debugfs_ function, there's nothing you can do here, just keep calling it :) And you will not get an error, you will only get NULL if there is an error, as the only error you would get is if debugfs was not enabled. > +static struct dentry *xhci_debugfs_create_ring_dir(struct xhci_hcd *xhci, > + struct xhci_ring *ring, > + const char *name, > + struct dentry *parent) > +{ > + struct dentry *dir; > + > + dir = debugfs_create_dir(name, parent); > + if (IS_ERR_OR_NULL(dir)) > + return NULL; Same here. Just keep going, you don't care about the return value, but you can use it safely no matter what. Same for other places in this patch as well. thanks, greg k-h -- To unsubscribe from this list: send the line "unsubscribe linux-usb" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html