[PATCH -next 2/5] ASoC: fsl_asrc: force cast the asrc_format type

[Shengjiu Wang]

On Tue, Jul 19, 2022 at 6:34 PM David Laight <David.Laight at aculab.com>
wrote:

> From: Mark Brown
> > Sent: 19 July 2022 11:17
> >
> > On Tue, Jul 19, 2022 at 10:01:54AM +0000, David Laight wrote:
> > > From: Shengjiu Wang
> >
> > > > - ret = of_property_read_u32(np, "fsl,asrc-format",
> &asrc->asrc_format);
> > > > + ret = of_property_read_u32(np, "fsl,asrc-format", (u32
> *)&asrc->asrc_format);
> >
> > > Ugg, you really shouldn't need to do that.
> > > It means that something is badly wrong somewhere.
> > > Casting pointers to integer types is just asking for a bug.
> >
> > That's casting one pointer type to another pointer type.
>
> It is casting the address of some type to a 'u32 *'.
> This will then be dereferenced by the called function.
> So the original type better be 32 bits.
>
> I'm also guessing that sparse was complaining about endianness?
> It isn't at all clear that these casts actually fix it.
>
> The sparse is complaining about the snd_pcm_format_t cast to u32/int type.

The code in include/sound/pcm.h also does such __force cast.
#define _SNDRV_PCM_FMTBIT(fmt)          (1ULL << (__force
int)SNDRV_PCM_FORMAT_##fmt)

The change I have made does not cause an issue.

Best regards
Wang shengjiu


> (Mark: You'll be glad to hear that the office aircon is
> broken again - two weeks lead time on the spare part.)
>
>         David
>
> -
> Registered Address Lakeside, Bramley Road, Mount Farm, Milton Keynes, MK1
> 1PT, UK
> Registration No: 1397386 (Wales)
>
>