Re: [PATCH] regulator: max8925: fix compiler warnings

[Qing Xu]

On 11/25/2012 01:55 AM, Mark Brown wrote:
> On Fri, Nov 23, 2012 at 10:27:12AM +0800, Qing Xu wrote:
>
> > But, in fact, it is not necessary to initialize regulator_idx.
> >          for (i = 0; i < ARRAY_SIZE(max8925_regulator_info); i++) {
> >                  ri = &max8925_regulator_info[i];
> >                  if (ri->vol_reg == res->start) {
> > ****** if regulator_idx can not get a match "i" here, it will return
> > -EINVAL in below code
> >                          regulator_idx = i;
> >                          break;
> >                  }
> >          }
> >          if (i == ARRAY_SIZE(max8925_regulator_info)) {
> >                  dev_err(&pdev->dev, "Failed to find regulator %llu\n",
> >                          (unsigned long long)res->start);
> >                  return -EINVAL;
> >          }
> > How to solve such compiler warning?
> Typically by reporting a compiler bug, though sometimes in the process
> of doing that one finds out that there's some non-obvious way in which
> the code can break.

It seems not like a compiler bug, its logic is:

for(...; i<xxx; ...) {
    if (...) {
        regulator_idx = i
        break;
    }
}

if (i == xxx)
    return ERROR;

If regulator_idx can not get a matched "i" value, code will return ERROR.
But it seems that compiler can not do so complex judge.
And, I think the code is safe even if regulator_idx is not initialized, also
because of the "return ERROR" judge.



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