| Message ID | 20170116110517.3833976-1-arnd@arndb.de (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
On Mon, 16 Jan 2017 12:04:56 +0100, Arnd Bergmann wrote: > > MIPS allmodconfig results in this warning: > > sound/mips/hal2.c: In function 'hal2_gain_get': > sound/mips/hal2.c:224:35: error: 'r' may be used uninitialized in this function [-Werror=maybe-uninitialized] > sound/mips/hal2.c:223:35: error: 'l' may be used uninitialized in this function [-Werror=maybe-uninitialized] > sound/mips/hal2.c: In function 'hal2_gain_put': > sound/mips/hal2.c:260:13: error: 'new' may be used uninitialized in this function [-Werror=maybe-uninitialized] > sound/mips/hal2.c:260:13: error: 'old' may be used uninitialized in this function [-Werror=maybe-uninitialized] > > It's easy enough to avoid by adding a 'default' clause to the switch > statements here. I assume that in practice no other case can happen, > but adding a default puts us on the safe side and shuts up the warnings. Well, these cases are logical errors that must not happen, so returning an error would be a "safer", IMO. thanks, Takashi > > Signed-off-by: Arnd Bergmann <arnd@arndb.de> > --- > sound/mips/hal2.c | 6 ++++++ > 1 file changed, 6 insertions(+) > > diff --git a/sound/mips/hal2.c b/sound/mips/hal2.c > index ede449f0b50d..0af4f7a9b3e7 100644 > --- a/sound/mips/hal2.c > +++ b/sound/mips/hal2.c > @@ -219,6 +219,9 @@ static int hal2_gain_get(struct snd_kcontrol *kcontrol, > l = (tmp >> H2I_C2_L_GAIN_SHIFT) & 15; > r = (tmp >> H2I_C2_R_GAIN_SHIFT) & 15; > break; > + default: > + l = 0; > + r = 0; > } > ucontrol->value.integer.value[0] = l; > ucontrol->value.integer.value[1] = r; > @@ -256,6 +259,9 @@ static int hal2_gain_put(struct snd_kcontrol *kcontrol, > new |= (r << H2I_C2_R_GAIN_SHIFT); > hal2_i_write32(hal2, H2I_ADC_C2, new); > break; > + default: > + new = 0; > + old = 0; > } > return old != new; > } > -- > 2.9.0 > >
On Mon, Jan 16, 2017 at 1:28 PM, Takashi Iwai <tiwai@suse.de> wrote: > On Mon, 16 Jan 2017 12:04:56 +0100, > Arnd Bergmann wrote: >> It's easy enough to avoid by adding a 'default' clause to the switch >> statements here. I assume that in practice no other case can happen, >> but adding a default puts us on the safe side and shuts up the warnings. > > Well, these cases are logical errors that must not happen, so > returning an error would be a "safer", IMO. Agreed. I sent out a v2 now. Arnd
diff --git a/sound/mips/hal2.c b/sound/mips/hal2.c index ede449f0b50d..0af4f7a9b3e7 100644 --- a/sound/mips/hal2.c +++ b/sound/mips/hal2.c @@ -219,6 +219,9 @@ static int hal2_gain_get(struct snd_kcontrol *kcontrol, l = (tmp >> H2I_C2_L_GAIN_SHIFT) & 15; r = (tmp >> H2I_C2_R_GAIN_SHIFT) & 15; break; + default: + l = 0; + r = 0; } ucontrol->value.integer.value[0] = l; ucontrol->value.integer.value[1] = r; @@ -256,6 +259,9 @@ static int hal2_gain_put(struct snd_kcontrol *kcontrol, new |= (r << H2I_C2_R_GAIN_SHIFT); hal2_i_write32(hal2, H2I_ADC_C2, new); break; + default: + new = 0; + old = 0; } return old != new; }
MIPS allmodconfig results in this warning: sound/mips/hal2.c: In function 'hal2_gain_get': sound/mips/hal2.c:224:35: error: 'r' may be used uninitialized in this function [-Werror=maybe-uninitialized] sound/mips/hal2.c:223:35: error: 'l' may be used uninitialized in this function [-Werror=maybe-uninitialized] sound/mips/hal2.c: In function 'hal2_gain_put': sound/mips/hal2.c:260:13: error: 'new' may be used uninitialized in this function [-Werror=maybe-uninitialized] sound/mips/hal2.c:260:13: error: 'old' may be used uninitialized in this function [-Werror=maybe-uninitialized] It's easy enough to avoid by adding a 'default' clause to the switch statements here. I assume that in practice no other case can happen, but adding a default puts us on the safe side and shuts up the warnings. Signed-off-by: Arnd Bergmann <arnd@arndb.de> --- sound/mips/hal2.c | 6 ++++++ 1 file changed, 6 insertions(+)