On Thu, Aug 09, 2018 at 01:43:58PM +0300, Dan Carpenter wrote: > On Thu, Aug 09, 2018 at 01:08:38PM +0300, Dan Carpenter wrote: > > On Thu, Aug 09, 2018 at 12:13:06PM +0530, Ajay Singh wrote: > > > wilc_dir = debugfs_create_dir("wilc_wifi", NULL); > > > - for (i = 0; i < ARRAY_SIZE(debugfs_info); i++) { > > > - info = &debugfs_info[i]; > > > - debugfs_create_file(info->name, > > > - info->perm, > > > - wilc_dir, > > > - &info->data, > > > - &info->fops); > > > + if (IS_ERR_OR_NULL(wilc_dir)) { > > > + pr_err("Error creating debugfs\n"); > > > + return -EFAULT; > > > } > > > > Just check for NULL. If someone builds without debugfs enabled in their > > .config, that's their choice. No need to print a warning. > > > > Reading it again, I'm not sure my email was clear... Just do this: > > wilc_dir = debugfs_create_dir("wilc_wifi", NULL); > if (!wilc_dir)) { > pr_err("Error creating debugfs/wilc_wifi/\n"); > return; > } > > If debugfs_create_dir() returns an error pointer it means all the other > debugfs functions are also just no-op stub functions. Passing an error > pointer to them is harmless. No, please never care about the return value of a debugfs call, it should never cause your code flow to do anything different. THis should just be: wilc_dir = debugfs_create_dir("wilc_wifi", NULL); and then keep on going. You can always pass the return value of a debugfs call to another one, no need to check anything. I've done a large sweep of the kernel tree for most of this pattern for 4.18, and will keep doing it over time, as it keeps creeping back. greg k-h _______________________________________________ devel mailing list devel@xxxxxxxxxxxxxxxxxxxxxx http://driverdev.linuxdriverproject.org/mailman/listinfo/driverdev-devel