Re: [PATCH] ASoC: generic: keep fallback dai_name stable across rebind

[Cássio Gabriel Monteiro Pires]

Hi, Kuninori

On 3/26/26 22:11, Kuninori Morimoto wrote:
> 
> Hi Cássio
> 
> Thank you for your patch
> 
>> simple_parse_dai() and graph_util_parse_dai() first try to identify a
>> DAI via dai_args. When that works the card can rebind without relying on
>> dlc->dai_name.
>>
>> The fallback path still calls snd_soc_get_dlc(), which returns a
>> borrowed dai_name pointer. If the CPU or codec component is unbound
>> while the sound card stays registered, the generic card keeps that
>> pointer and the next rebind may compare stale memory while matching the
>> DAI.
>>
>> Stage the fallback result in a temporary dai_link_component and move
>> only a card-owned copy of dai_name into the live link component. Use
>> devm_kstrdup_const() so static names are reused and dynamic ones remain
>> valid for the lifetime of the card device.
>>
>> Signed-off-by: Cássio Gabriel <cassiogabrielcontato@xxxxxxxxx>
>> ---
> 
> It looks good to me.
> 
> Acked-by: Kuninori Morimoto <kuninori.morimoto.gx@xxxxxxxxxxx>
> 
> 1 concern is that this function is using goto, ad your code is fixing
> (A) part.
> 
> 	int graph_util_parse_dai(...)
> 	{
> 		...
> 		dai = snd_soc_get_dai_via_args(...);
> 		if (dai) {
> 			...
> =>			goto parse_dai_end;
> 		}
> 
> (A)		...
> 
> 	parse_dai_end:
> 		...
> 	}
> 
> 
> I think it is good timing to use if-else here ?
> 
> 	int graph_util_parse_dai(...)
> 	{
> 		...
> 		dai = snd_soc_get_dai_via_args(...);
> 		if (dai) {
> 			...
> +		} else {
> + (A)			...
> +		}
> 		...
> 	}
> 
> 

That makes sense, and it’s clearer.
I’m going to send the v2 patch with the changes.

> 
> Thank you for your help !!
> 
> Best regards
> ---
> Kuninori Morimoto

-- 
Thanks,
Cássio