In the function kirkwood_set_rate, when the rate cannot be satisfied by the internal nor by an external clock, the clock source in undefined:
warning: ‘clks_ctrl’ may be used uninitialized in this function
The ALSA subsystem should never gives such a rate because: - the rates with the internal clock are limited to 44.1, 48 and 96 kHz as specified by the kirkwood_i2s_dai structure, - the other rates are proposed in the structure kirkwood_i2s_dai_extclk only when the external clock is present.
In case of programming error (bad rate for internal clock and no external clock), the function will simply cause a backtrace.
Signed-off-by: Jean-Francois Moine moinejf@free.fr --- v2 - add more explanations --- sound/soc/kirkwood/kirkwood-i2s.c | 8 +++++--- 1 file changed, 5 insertions(+), 3 deletions(-)
diff --git a/sound/soc/kirkwood/kirkwood-i2s.c b/sound/soc/kirkwood/kirkwood-i2s.c index 4c9dad3..c9daf3b 100644 --- a/sound/soc/kirkwood/kirkwood-i2s.c +++ b/sound/soc/kirkwood/kirkwood-i2s.c @@ -105,14 +105,16 @@ static void kirkwood_set_rate(struct snd_soc_dai *dai, uint32_t clks_ctrl;
if (rate == 44100 || rate == 48000 || rate == 96000) { - /* use internal dco for supported rates */ + /* use internal dco for the supported rates + * defined in kirkwood_i2s_dai */ dev_dbg(dai->dev, "%s: dco set rate = %lu\n", __func__, rate); kirkwood_set_dco(priv->io, rate);
clks_ctrl = KIRKWOOD_MCLK_SOURCE_DCO; - } else if (!IS_ERR(priv->extclk)) { - /* use optional external clk for other rates */ + } else { + /* use the external clock for the other rates + * defined in kirkwood_i2s_dai_extclk */ dev_dbg(dai->dev, "%s: extclk set rate = %lu -> %lu\n", __func__, rate, 256 * rate); clk_set_rate(priv->extclk, 256 * rate);