On Tue, Apr 16, 2019 at 10:55:33PM +0200, Wolfram Sang wrote: > > > That is indeed a problem: the pointer will be NULL if there is no parent > > device (such as in softdog.c). Otherwise it should never be NULL. > > Okay, this spoils my err_dev solution. So, we probably go this route > then: > > pr_<errlvl>("watchdog%d: <err_msg>\n", wdd->id); > I don't like it because it doesn't show the driver name, and watchdog%d can change with each reboot. How about something like this ? static void pr_wdt_err(struct watchdog_device *wdd, char *text, int err) { if (wdd->parent) dev_err(wdd->parent, "%s: %d\n", text, err); else pr_err("%s: %s: %d\n", wdd->info->identity, text, err); } We could then use the same mechanism to generate error messages for watchdog_register_device(). Guenter