ASoC: rsnd: fix usrcnt decrementing bug
authorAndrzej Hajda <a.hajda@samsung.com>
Thu, 24 Dec 2015 07:02:39 +0000 (08:02 +0100)
committerMark Brown <broonie@kernel.org>
Wed, 30 Dec 2015 17:13:20 +0000 (17:13 +0000)
Field usrcnt is unsigned so it cannot be lesser than zero.
The patch fixes the check, moves it to the beginning of the function
and changes return value to -EIO in case of usercnt error.

The problem has been detected using proposed semantic patch
scripts/coccinelle/tests/unsigned_lesser_than_zero.cocci [1].

[1]: http://permalink.gmane.org/gmane.linux.kernel/2038576

Signed-off-by: Andrzej Hajda <a.hajda@samsung.com>
Acked-by: Kuninori Morimoto <kuninori.morimoto.gx@renesas.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
sound/soc/sh/rcar/ssi.c

index 7db05fd..7ee89da 100644 (file)
@@ -403,29 +403,30 @@ static int rsnd_ssi_quit(struct rsnd_mod *mod,
        struct rsnd_ssi *ssi = rsnd_mod_to_ssi(mod);
        struct device *dev = rsnd_priv_to_dev(priv);
 
-       if (rsnd_ssi_is_parent(mod, io))
-               goto rsnd_ssi_quit_end;
+       if (!ssi->usrcnt) {
+               dev_err(dev, "%s[%d] usrcnt error\n",
+                       rsnd_mod_name(mod), rsnd_mod_id(mod));
+               return -EIO;
+       }
 
-       if (ssi->err > 0)
-               dev_warn(dev, "%s[%d] under/over flow err = %d\n",
-                        rsnd_mod_name(mod), rsnd_mod_id(mod), ssi->err);
+       if (!rsnd_ssi_is_parent(mod, io)) {
+               if (ssi->err > 0)
+                       dev_warn(dev, "%s[%d] under/over flow err = %d\n",
+                                rsnd_mod_name(mod), rsnd_mod_id(mod),
+                                ssi->err);
 
-       ssi->cr_own     = 0;
-       ssi->err        = 0;
+               ssi->cr_own     = 0;
+               ssi->err        = 0;
 
-       rsnd_ssi_irq_disable(mod);
+               rsnd_ssi_irq_disable(mod);
+       }
 
-rsnd_ssi_quit_end:
        rsnd_ssi_master_clk_stop(ssi, io);
 
        rsnd_mod_power_off(mod);
 
        ssi->usrcnt--;
 
-       if (ssi->usrcnt < 0)
-               dev_err(dev, "%s[%d] usrcnt error\n",
-                       rsnd_mod_name(mod), rsnd_mod_id(mod));
-
        return 0;
 }