[PATCH v2 1/4] mtd: cfi_cmdset_0002: Add support for reading OTP

[Artem Bityutskiy]

On Wed, 2013-05-29 at 14:54 +0200, Christian Riesch wrote:
> Artem,
> Thank you very much for your comments!
> 
> On 2013-05-29 09:11, Artem Bityutskiy wrote:
> > On Fri, 2013-04-26 at 21:10 +0200, Christian Riesch wrote:
> >> +static int cfi_amdstd_get_fact_prot_info(struct mtd_info *mtd,
> >> +                                          struct otp_info *buf,
> >> size_t len)
> >> +{
> >> +       size_t retlen;
> >> +       int ret;
> >> +
> >> +       ret = cfi_amdstd_otp_walk(mtd, 0, len, &retlen, (u_char *)buf,
> >> NULL, 0);
> >> +       return ret ? : retlen;
> >> +}
> >
> > Hmm, I thought we would return 0 in case of success and a negative error
> > code in case of error. Returning retlen looks wrong.
> >
> 
> I don't think so. Somehow the caller of this function should be told how 
> many bytes have been written into buf, there is no other way to return 
> the data length than the return value. Anyway, I just stole this code 
> from cfi_cmdset_0001.c (function cfi_intelext_get_fact_prot_info), it is 
> done in the same way there.

But retlen is where you return the amount of bytes you actually wrote.
The return code is either 0 or a negative error code number. This is
what we do in mtd_write() and I'd expect the OTP functions to be
consistent.

-- 
Best Regards,
Artem Bityutskiy