Re: SB16 build error.

From: Ralf Baechle
Date: Thu Jun 30 2011 - 08:44:04 EST


On Thu, Jun 30, 2011 at 02:38:20PM +0200, Takashi Iwai wrote:

> > In userland an empty definition will be used for _IOC_TYPECHECK so there
> > won't be an error. So userland already is already using the existing
> > value for SNDRV_SB_CSP_IOCTL_LOAD_CODE ...
>
> Right. It has an invalid direction (3), but apps won't care such
> details anyway.
>
> > With a crude hack like
> >
> > #define SNDRV_SB_CSP_IOCTL_LOAD_CODE \
> > _IOC(_IOC_WRITE,'H', 0x11, sizeof(struct snd_sb_csp_microcode))
> >
> > error checking can be bypassed and all will be fine as long as the
> > resulting value doesn't result in in a a duplicate case value - which it
> > doesn't, at least not in my testing.
> >
> > Should work but isn't nice.
>
> Indeed. But which is uglier is hard to answer :)
>
> If you are fine with the hacked ioctl number above, I can put it
> with some comments. This won't break anything, at least.

Go ahead then and yes, this really deserves a comment.

Ralf
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/