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 <moin...@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);
--
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