At Mon, 12 Jan 2009 14:42:06 +0000,
James Courtier-Dutton wrote:
>
> Sounds good to me.
> One can keep the wrapper outside of the kernel, and only available in
> alsa-driver for those out of tree people.
Yes, that's good.
I think it'd be better to do that after one kernel-cycle later for a
softer landing, though.
thanks,
Takashi
> Kind Regards
>
> James
>
>
>
>
> 2009/1/12 Takashi Iwai <tiwai@xxxxxxx>:
> > Hi,
> >
> > so far, we use snd_card_new() function to create a card instance.
> > A known problem regarding this API is that it doesn't return a proper
> > error code, thus the probe callback always returns -ENOMEM (or
> > whatever the driver defines) no matter which error occurred actually.
> > A typical case is the card slot conflict. Even in such a case, it
> > returns -ENOMEM, which may mislead the user.
> >
> > For fixing this situation, I'd like to convert from snd_card_new() to
> > a new function, snd_card_create():
> >
> > int snd_card_create(int idx, const char *id,
> > struct module *module, int extra_size,
> > struct snd_card **card_ret);
> >
> > and provides snd_card_new() as a wrapper with deprecated flag:
> >
> > static inline __deprecated
> > struct snd_card *snd_card_new(int idx, const char *id,
> > struct module *module, int extra_size)
> > {
> > struct snd_card *card;
> > if (snd_card_create(idx, id, module, extra_size, &card) < 0)
> > return NULL;
> > return card;
> > }
> >
> > The merit of creating a new function is that the older and out-of-tree
> > codes (like xfi) work without modification. There is alternative
> > option, namely to use PTR_ERR() and keep the function as is.
> > But this has no advantage in practice -- it can't detect the old API
> > at build time, and it may Oops.
> >
> > The preliminary patches are found in test/snd_card_new-err branch
> > of sound git tree:
> > git://git.kernel.org/pub/scm/linux/kernel/git/tiwai/sound-2.6.git test/snd_card_new-err
> >
> > If anyone finds problems with this, please let me know.
> >
> >
> > thanks,
> >
> > Takashi
> > _______________________________________________
> > Alsa-devel mailing list
> > Alsa-devel@xxxxxxxxxxxxxxxx
> > http://mailman.alsa-project.org/mailman/listinfo/alsa-devel
> >
>
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