Re: [PATCH] driver core: Make dev_err_probe() silent for -ENOMEM

From: Andy Shevchenko
Date: Fri Apr 12 2024 - 13:08:12 EST


On Fri, Apr 12, 2024 at 07:03:01PM +0200, Uwe Kleine-König wrote:
> On Fri, Apr 12, 2024 at 07:51:48PM +0300, Andy Shevchenko wrote:
> > On Fri, Apr 12, 2024 at 06:44:05PM +0200, Uwe Kleine-König wrote:
> > > For an out-of-memory error there should be no additional output. Adapt
> > > dev_err_probe() to not emit the error message when err is -ENOMEM.
> > > This simplifies handling errors that might among others be -ENOMEM.

> > ...
> >
> > BUILD_BUG_ON(err == -ENOMEM);
> >
> > Done!
>
> Well no, that doesn't do the trick. Consider for example device_add().
> That function can return (at least) -EINVAL and -ENOMEM. To properly
> ensure that the error handling is silent with the current
> dev_err_probe(), we'd need to do:
>
> ret = device_add(...);
> if (ret) {
> if (ret != -ENOMEM)
> return dev_err_probe(...);
> else
> return ret;
> }
>
> With my suggested patch this can be reduced to:
>
> ret = device_add(...);
> if (ret)
> return dev_err_probe(...);

Fair enough, but these two should be combined.
Mine is for the rejecting a dead code on the phase of the submission.

--
With Best Regards,
Andy Shevchenko