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 structures.
Switch from macro to inline function, so such mistake will be build-time
detectable.
Signed-off-by: Krzysztof Kozlowski <[email protected]>
---
include/sound/soc.h | 8 ++++++--
1 file changed, 6 insertions(+), 2 deletions(-)
diff --git a/include/sound/soc.h b/include/sound/soc.h
index 2a1b6c198547..cacaa92487a0 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 substream->private_data;
+}
#define for_each_rtd_components(rtd, i, component) \
for ((i) = 0, component = NULL; \
--
2.43.0
On Tue, Apr 30, 2024 at 04:09:38PM +0200, Krzysztof Kozlowski wrote:
> -#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 substream->private_data;
> +}
This is not an obvious direct substitution, we've skipped the
snd_pcm_subsystem_chip() (which is also a macro, but that just suggests
it could do with it's own cleanup) and the commit log didn't mention it.
On 30/04/2024 16:56, Mark Brown wrote:
> On Tue, Apr 30, 2024 at 04:09:38PM +0200, Krzysztof Kozlowski wrote:
>
>> -#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 substream->private_data;
>> +}
>
> This is not an obvious direct substitution, we've skipped the
> snd_pcm_subsystem_chip() (which is also a macro, but that just suggests
> it could do with it's own cleanup) and the commit log didn't mention it.
Yes, you're right. I should keep snd_pcm_substream_chip().
Best regards,
Krzysztof