ASoC: Use inline function for type safety in snd_soc_substream_to_rtd()
A common pattern in sound drivers is getting 'struct snd_soc_pcm_runtime'
from 'struct snd_pcm_substream' opaque pointer private_data field with
snd_soc_substream_to_rtd(). However 'private_data' appears in several
other structures as well, including 'struct snd_compr_stream'. The
field might not hold the same type for every structure, although seems
the case at least for 'struct snd_compr_stream', so code can easily make
a mistake by using macro for wrong structure passed as argument.
Switch from macro to inline function, so such mistake will be build-time
detectable.
Signed-off-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Link: https://lore.kernel.org/r/20240501175127.34301-1-krzysztof.kozlowski@linaro.org
Signed-off-by: Mark Brown <broonie@kernel.org>
diff --git a/include/sound/soc.h b/include/sound/soc.h
index 8aa6ddb7..3367143 100644
--- a/include/sound/soc.h
+++ b/include/sound/soc.h
@@ -1215,8 +1215,12 @@ struct snd_soc_pcm_runtime {
/* see soc_new_pcm_runtime() */
#define snd_soc_rtd_to_cpu(rtd, n) (rtd)->dais[n]
#define snd_soc_rtd_to_codec(rtd, n) (rtd)->dais[n + (rtd)->dai_link->num_cpus]
-#define snd_soc_substream_to_rtd(substream) \
- (struct snd_soc_pcm_runtime *)snd_pcm_substream_chip(substream)
+
+static inline struct snd_soc_pcm_runtime *
+snd_soc_substream_to_rtd(const struct snd_pcm_substream *substream)
+{
+ return snd_pcm_substream_chip(substream);
+}
#define for_each_rtd_components(rtd, i, component) \
for ((i) = 0, component = NULL; \
