Messages in this thread Patch in this message | | | From | Coiby Xu <> | Date | Wed, 16 Sep 2020 19:17:12 +0800 | Subject | Re: [PATCH] staging: greybus: fix warnings detected by sparse |
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On Mon, Aug 24, 2020 at 12:41:48PM +0300, Dan Carpenter wrote: >On Mon, Aug 24, 2020 at 10:50:59AM +0800, Coiby Xu wrote: >> This patch fix the following warnings from sparse, >> >> $ make C=2 drivers/staging/greybus/ >> drivers/staging/greybus/audio_codec.c:691:36: warning: incorrect type in initializer (different base types) >> drivers/staging/greybus/audio_codec.c:691:36: expected unsigned long long [usertype] formats >> drivers/staging/greybus/audio_codec.c:691:36: got restricted snd_pcm_format_t [usertype] >> drivers/staging/greybus/audio_codec.c:701:36: warning: incorrect type in initializer (different base types) >> drivers/staging/greybus/audio_codec.c:701:36: expected unsigned long long [usertype] formats >> drivers/staging/greybus/audio_codec.c:701:36: got restricted snd_pcm_format_t [usertype] >> drivers/staging/greybus/audio_module.c:222:25: warning: incorrect type in assignment (different base types) >> drivers/staging/greybus/audio_module.c:222:25: expected restricted __le16 [usertype] data_cport >> drivers/staging/greybus/audio_module.c:222:25: got unsigned short [usertype] intf_cport_id >> drivers/staging/greybus/audio_topology.c:460:40: warning: restricted __le32 degrades to integer >> drivers/staging/greybus/audio_topology.c:691:41: warning: incorrect type in assignment (different base types) >> drivers/staging/greybus/audio_topology.c:691:41: expected unsigned int access >> drivers/staging/greybus/audio_topology.c:691:41: got restricted __le32 [usertype] access >> drivers/staging/greybus/audio_topology.c:746:44: warning: incorrect type in assignment (different base types) >> drivers/staging/greybus/audio_topology.c:746:44: expected unsigned int >> drivers/staging/greybus/audio_topology.c:746:44: got restricted __le32 >> drivers/staging/greybus/audio_topology.c:748:52: warning: incorrect type in assignment (different base types) >> drivers/staging/greybus/audio_topology.c:748:52: expected unsigned int >> drivers/staging/greybus/audio_topology.c:748:52: got restricted __le32 >> drivers/staging/greybus/audio_topology.c:802:42: warning: restricted __le32 degrades to integer >> drivers/staging/greybus/audio_topology.c:805:50: warning: incorrect type in assignment (different base types) >> drivers/staging/greybus/audio_topology.c:805:50: expected restricted __le32 >> drivers/staging/greybus/audio_topology.c:805:50: got unsigned int >> drivers/staging/greybus/audio_topology.c:814:50: warning: restricted __le32 degrades to integer >> drivers/staging/greybus/audio_topology.c:817:58: warning: incorrect type in assignment (different base types) >> drivers/staging/greybus/audio_topology.c:817:58: expected restricted __le32 >> drivers/staging/greybus/audio_topology.c:817:58: got unsigned int >> drivers/staging/greybus/audio_topology.c:889:25: warning: incorrect type in assignment (different base types) >> drivers/staging/greybus/audio_topology.c:889:25: expected unsigned int access >> drivers/staging/greybus/audio_topology.c:889:25: got restricted __le32 [usertype] access >> >> Signed-off-by: Coiby Xu <coiby.xu@gmail.com> >> --- >> drivers/staging/greybus/audio_codec.c | 4 ++-- >> drivers/staging/greybus/audio_module.c | 2 +- >> drivers/staging/greybus/audio_topology.c | 18 +++++++++--------- >> 3 files changed, 12 insertions(+), 12 deletions(-) >> >> diff --git a/drivers/staging/greybus/audio_codec.c b/drivers/staging/greybus/audio_codec.c >> index 74538f8c5fa4..494aa823e998 100644 >> --- a/drivers/staging/greybus/audio_codec.c >> +++ b/drivers/staging/greybus/audio_codec.c >> @@ -688,7 +688,7 @@ static struct snd_soc_dai_driver gbaudio_dai[] = { >> .playback = { >> .stream_name = "I2S 0 Playback", >> .rates = SNDRV_PCM_RATE_48000, >> - .formats = SNDRV_PCM_FORMAT_S16_LE, >> + .formats = SNDRV_PCM_FMTBIT_S16_LE, >> .rate_max = 48000, >> .rate_min = 48000, >> .channels_min = 1, >> @@ -698,7 +698,7 @@ static struct snd_soc_dai_driver gbaudio_dai[] = { >> .capture = { >> .stream_name = "I2S 0 Capture", >> .rates = SNDRV_PCM_RATE_48000, >> - .formats = SNDRV_PCM_FORMAT_S16_LE, >> + .formats = SNDRV_PCM_FMTBIT_S16_LE, >> .rate_max = 48000, >> .rate_min = 48000, >> .channels_min = 1, > >These changes need to be explained better. We're changing formats from >2 to 1 << 2. > >When you're writing commit messages, please imagine me as the target >audience. I have a fairly decent understanding of the kernel and C, but >I don't know very much about the sound subsystem.
(Sorry for the late reply! I didn't notice my email client failed to delivered this email.)
Thank you for showing me SNDRV_PCM_FORMAT_S16_LE != SNDRV_PCM_FMTBIT_S16_LE. I thought they only differ in type so no domain knowledge is needed. > >This code used to work, right? How was it that changing a 2 to a 4 >makes it better? It needs to be explained in the commit message. This >change probably needs to be split into a separate commit because it >seems different from the rest of the patch.
After doing some homework on greybus, ALSA, PCM, etc., I think SNDRV_PCM_FORMAT_S16_LE could be a mistake,
1. According to the struct definition,
struct snd_soc_dai_driver { ... /* DAI capabilities */ struct snd_soc_pcm_stream capture; struct snd_soc_pcm_stream playback; /* SoC PCM stream information */
struct snd_soc_pcm_stream { const char *stream_name; u64 formats; /* SNDRV_PCM_FMTBIT_* */ ... };
We should use SNDRV_PCM_FMTBIT_* which is a bit mask while SNDRV_PCM_FORMAT_* are sequential integers.
2. This "formats" member represent PCM audio's resolution/sample Size, Byte Order and Sign [1]. In terms of the values, SNDRV_PCM_FORMAT_S16_LE == SNDRV_PCM_FMTBIT_S8. Using 8 bits to represent the amplitude of the sound sample may lead to low quality audio.
3. There is this commit e712bfca1ac1f63f622f87c2f33b57608f2a4d19 ("ASoC: codecs: use SNDRV_PCM_FMTBIT_* for format bitmask"),
snd_soc_pcm_stream.formats is a bitmask of SNDRV_PCM_FMTBIT_*, not of SNDRV_PCM_FORMAT_* (which are sequential integers), however some of ASoC CODEC drivers use these values instead.
which simply replaced SNDRV_PCM_FORMAT_S16_LE with SNDRV_PCM_FMTBIT_S16_LE.
> >(Presumably the rest of the patch doesn't affect runtime on little >endian systems. This is the part which affects runtime so it is >different from the rest). > >> diff --git a/drivers/staging/greybus/audio_module.c b/drivers/staging/greybus/audio_module.c >> index 16f60256adb2..00848b84b022 100644 >> --- a/drivers/staging/greybus/audio_module.c >> +++ b/drivers/staging/greybus/audio_module.c >> @@ -219,7 +219,7 @@ static int gb_audio_add_data_connection(struct gbaudio_module_info *gbmodule, >> >> greybus_set_drvdata(bundle, gbmodule); >> dai->id = 0; >> - dai->data_cport = connection->intf_cport_id; >> + dai->data_cport = cpu_to_le16(connection->intf_cport_id); >> dai->connection = connection; >> list_add(&dai->list, &gbmodule->data_list); >> > >This is correct, but I think you should change the two places which >print the data_cport to print the CPU endian value. > > 327 list_for_each_entry(dai, &gbmodule->data_list, list) { > 328 ret = gb_connection_enable(dai->connection); > 329 if (ret) { > 330 dev_err(dev, > 331 "%d:Error while enabling %d:data connection\n", > 332 ret, dai->data_cport); > 333 goto disable_data_connection; > 334 } > 335 } > > 449 list_for_each_entry(dai, &gbmodule->data_list, list) { > 450 ret = gb_connection_enable(dai->connection); > 451 if (ret) { > 452 dev_err(dev, > 453 "%d:Error while enabling %d:data connection\n", > 454 ret, dai->data_cport); > 455 return ret; > 456 } > 457 } > >Otherwise it's slightly confusing to mix the values.
Thank you for the suggestion! I'll fix it in next version. > >The rest of the patch seems fine to me. > >regards, >dan carpenter > Thank you for reviewing this patch!
[1] https://wiki.multimedia.cx/index.php/PCM
-- Best regards, Coiby
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