回复: S905x: No sound with error log.

[Jerome Brunet]

On Wed 29 Jul 2020 at 04:16, 张 宁 <zhangn1985 at outlook.com> wrote:

> any progress on this issue?
>
> I have tried to remove link->dpcm_capture = 1; this fix the issue, but I don't know whether there any side effect.
>
> my patch: https://github.com/zhangn1985/linux/commit/b88a7df8adfdd80bc6a0802ce64797f17c0a7d32
>

As you may have seen, there is some discussion around this topic ATM.
Until something concrete lands, the easiest thing to do is to revert
b73287f0b074 ("ASoC: soc-pcm: dpcm: fix playback/capture checks")

The card should work again with that. Sorry for the inconvenience.

Jerome

> ________________________________
> 发件人: Jerome Brunet <jbrunet at baylibre.com>
> 发送时间: 2020年7月17日 10:12
> 收件人: Pierre-Louis Bossart <pierre-louis.bossart at linux.intel.com>; 张 宁 <zhangn1985 at outlook.com>
> 抄送: linux-amlogic at lists.infradead.org <linux-amlogic at lists.infradead.org>
> 主题: Re: S905x: No sound with error log.
>
>
> On Thu 16 Jul 2020 at 04:37, Pierre-Louis Bossart <pierre-louis.bossart at linux.intel.com> wrote:
>
>> On 7/15/20 5:04 PM, 张 宁 wrote:
>>> Hi,
>>>
>>> Recent asoc change makes S905x audio card prob failed.
>>>
>>> [    6.338428] gx-sound-card sound: CPU DAI I2S Encoder for rtd be.dai-link-1 does not support capture
>>> [    6.342176] gx-sound-card sound: ASoC: can't create pcm be.dai-link-1 :-22
>>>
>>> Good: 5.7.3
>>> Bad: 5.7.6
>>>
>>> After read patches, I find suspect:
>>>
>>> https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/sound/soc?h=v5.7.8&id=1bb707fbfd5c246028d76b8f11a19dfd118d6306
>>>
>>> this patch doesn’t allow playback only or capture only dai-link. Why?
>>
>> it does, but you need to make sure the capabilities of a dai match the
>> capability of a dailink they are part of. The be-dai-link1 can support
>> capture but the I2S encoder so doesn't you have an invalid configuration.
>>
>> Could this be the problem be with this code:
>>
>> int meson_card_set_be_link(struct snd_soc_card *card,
>>                           struct snd_soc_dai_link *link,
>>                           struct device_node *node)
>> {
>>        struct snd_soc_dai_link_component *codec;
>>        struct device_node *np;
>>        int ret, num_codecs;
>>
>>        link->no_pcm = 1;
>>        link->dpcm_playback = 1;
>>        link->dpcm_capture = 1;
>>
>
> Hi Pierre-Louis,
>
> actually this patch changed the meaning of the dpcm_playback and
> dpcm_capture from "is_allowed" to "is_required" and it broke this card
> and another one for me.
>
> Yes the flag are "blindly" set because with the old meanning, there was
> no reason to disallow any direction. Also the card driver only handles
> DT phandle and does not know much about the DAI (BE) caps.
>
> Your change in ASoC core was meant to add support for multi cpu BE link
> but:
>  - it changed the meaning of the flags
>  - it forces all CPU on the BE link to share the same direction
>  capability.
>
>> Setting the flags blindly is not so good. A helper was added recently,
>> see 25612477d20b ('ASoC: soc-dai: set dai_link dpcm_ flags with a
>> helper')
>
> Same with this change, if any codec does not support a stream direction,
> it gets disabled. But it is uncommon to have link with multiple codec,
> one for each stream direction. The commit above would break those cards
>
> Could you tell why it was not possible to retain the previous logic
> which was : disable the stream direction if
>  - dpcm_{capture,playback) is false OR
>  - no codec support the direction (same would apply to cpu)
>
> ??
>
>>
>>
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