On Tue, Apr 16, 2019 at 02:20:46PM -0700, Guenter Roeck wrote:
> 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().

'text' is a constant string then. Supporting a format string will make
this much more complicated. Yet, printing out the wrong timeout is
useful, I think.

What about:

	dev_str = wdd->parent ? dev_name(wdd->parent) : wdd->info->identity;
	pr_<errlvl>("%s: <errstr>\n", dev_str, ...);

?

This can be easily copied for watchdog_register_device, not much
overhead there.