Re: [alsa-devel] ASoC: rsnd: fix sound route path when using SRC6/SRC9

Hi Morimoto-san,

On Wed, May 17, 2017 at 3:32 AM, Kuninori Morimoto kuninori.morimoto.gx@renesas.com wrote:

...

...

@@ -70,16 +71,19 @@ static int rsnd_cmd_init(struct rsnd_mod *mod, } else { struct rsnd_mod *src = rsnd_io_to_mod_src(io);

•           u32 path[] = {
  

•                   [0] = 0x30000,
  

•                   [1] = 0x30001,
  

•                   [2] = 0x40000,
  

•                   [3] = 0x10000,
  

•                   [4] = 0x20000,
  

•                   [5] = 0x40100
  

•           u8 cmd_case[] = {
  

•                   [0] = 0x3,
  

•                   [1] = 0x3,
  

•                   [2] = 0x4,
  

•                   [3] = 0x1,
  

•                   [4] = 0x2,
  

•                   [5] = 0x4,
  

•                   [6] = 0x1,
  

•                   [9] = 0x2,
            };
  
  

•           data = path[rsnd_mod_id(src)];
  

•           data = path[rsnd_mod_id(src)] |
  

With gcc 4.9.0:

sound/soc/sh/rcar/cmd.c: In function 'rsnd_cmd_init':
sound/soc/sh/rcar/cmd.c:85:14: warning: array subscript is below

array bounds [-Warray-bounds] data = path[rsnd_mod_id(src)] |

Hmm.... I tried random code/compile, but gcc behavior seems strange. Fore example if I removed next line, this warning disappeard

•           data = path[rsnd_mod_id(src)] |
  

•                   cmd_case[rsnd_mod_id(src)] << 16;
  

•           data = path[rsnd_mod_id(src)];
  
  

Is this related to this ? https://gcc.gnu.org/bugzilla/show_bug.cgi?id=59124

Perhaps.

I guess the main question is: can src be NULL here? If yes, rsnd_mod_id(src) will be -1.

Gr{oetje,eeting}s,

Geert

-- Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@linux-m68k.org

In personal conversations with technical people, I call myself a hacker. But when I'm talking to journalists I just say "programmer" or something like that. -- Linus Torvalds