Re: [PATCH] sound: hdmi: avoid dereferencing uninitialized 'jack' pointer

From: Arnd Bergmann
Date: Tue Feb 16 2016 - 11:10:40 EST


On Tuesday 16 February 2016 16:49:42 Takashi Iwai wrote:
>
> Thanks for the patch. But I think it's cleaner to fix Kconfig.
>
> Thinking more of it, maybe splitting jack stuff as a separate module
> and does reverse-select to CONFIG_INPUT would be better. Then its
> users can select simply SND_JACK, and everything would fit.
>
>

Adding 'select INPUT' is rather nasty, I think that can lead to circular
dependencies, and would likely upset users of small embedded systems
that want to use audio but don't want to use input.

Generally speaking, I would recommend never using 'select' on a user
visible Kconfig symbol.

Another option might would be to change snd_jack_new() to return
an error if that SND_JACK is disabled, and then require all users
to handle the error gracefully, i.e. not fail the probe() function
but just not use the jack.

Arnd