Re: [PATCH] clk: vt8500: don't return possibly uninitialized data

[Arnd Bergmann <arnd@arndb.de>]

On Monday 01 February 2016 17:15:45 Stephen Boyd wrote:
> My compiler still gets warnings even after this patch is applied.
>=20
> drivers/clk/clk-vt8500.c: In function =E2=80=98wm8750_find_pll_bits=E2=
=80=99:
> drivers/clk/clk-vt8500.c:509:12: warning: =E2=80=98best_div2=E2=80=99=
 may be used uninitialized in this function [-Wmaybe-uninitialized]
> drivers/clk/clk-vt8500.c:508:12: warning: =E2=80=98best_div1=E2=80=99=
 may be used uninitialized in this function [-Wmaybe-uninitialized]
> drivers/clk/clk-vt8500.c:507:14: warning: =E2=80=98best_mul=E2=80=99 =
may be used uninitialized in this function [-Wmaybe-uninitialized]
> drivers/clk/clk-vt8500.c: In function =E2=80=98wm8650_find_pll_bits=E2=
=80=99:
> drivers/clk/clk-vt8500.c:430:12: warning: =E2=80=98best_div2=E2=80=99=
 may be used uninitialized in this function [-Wmaybe-uninitialized]
> drivers/clk/clk-vt8500.c:429:12: warning: =E2=80=98best_div1=E2=80=99=
 may be used uninitialized in this function [-Wmaybe-uninitialized]
> drivers/clk/clk-vt8500.c:428:14: warning: =E2=80=98best_mul=E2=80=99 =
may be used uninitialized in this function [-Wmaybe-uninitialized]
> drivers/clk/clk-vt8500.c: In function =E2=80=98wm8850_find_pll_bits=E2=
=80=99:
> drivers/clk/clk-vt8500.c:560:12: warning: =E2=80=98best_div2=E2=80=99=
 may be used uninitialized in this function [-Wmaybe-uninitialized]
> drivers/clk/clk-vt8500.c:559:12: warning: =E2=80=98best_div1=E2=80=99=
 may be used uninitialized in this function [-Wmaybe-uninitialized]
> drivers/clk/clk-vt8500.c:558:14: warning: =E2=80=98best_mul=E2=80=99 =
may be used uninitialized in this function [-Wmaybe-uninitialized]
>=20

I see what you mean now. I checked different gcc versions, and with my =
patch I get
the warnings for 4.6 through 4.9, but not for 5.x.

In general, I tried to only address warnings I still see with newer gcc=
 version,
as they are better about false positives. Do you think it's ok to take =
the
patch as is then? Otherwise we probably have to add fake initialization=
s which
would shut up the warnings but not help with the code quality.

=09Arnd