Re: [PATCH v3 1/2] ASoC: core: Add API to use DMI name in sound card long name

[Mengdong Lin <mengdong.lin@linux.intel.com>]

On 01/10/2017 03:09 PM, Takashi Iwai wrote:
> On Tue, 10 Jan 2017 07:42:49 +0100,
> mengdong.lin@linux.intel.com wrote:
>>
>> +/**
>> + * snd_soc_set_dmi_name() - Register DMI names to card
>> + * @card: The card to register DMI names
>> + * @flavour: The flavour "differentiator" for the card amongst its peers.
>> + *
>> + * An Intel machine driver may be used by many different devices but are
>> + * difficult for userspace to differentiate, since machine drivers ususally
>> + * use their own name as the card name (short name) and leave the card long
>> + * name blank. To differentiate such devices and fix bugs due to lack of
>> + * device-specific configurations, this function allows DMI info to be used
>> + * as the sound card long name, in the format of
>> + * "vendor.product.version.board"
>> + * (Character '.' are used to separate different DMI fields here).
>> + * This will help the userspace to load the correct UCM (Use Case Manager)
>> + * configuration.
>> + *
>> + * Possible card long names may be:
>> + * DellInc..XPS139343.01.0310JH
>> + * ASUSTeKCOMPUTERINC..T100TA.1.0.T100TA
>> + * Circuitco.MinnowboardMaxD0PLATFORM.D0.MinnowBoardMAX
>> + * (Please note DMI can also include '.' like"Inc." so you may see double '.
> '
>> + * sometimes)
>
> Looking at the examples above, I wonder whether the dot is the best
> choice as the separator.  Might other letters (e.g. ":" or "=") would
> be clearer?  The colon might be bad if it were combined with the
> alsa-lib plugin syntax, but I guess it won't happen?
>

Hi Takashi,

I found we cannot use ":" as separator. It's because we want to use the 
card long name as the name of the directory to store UCM configuration 
files for this card, and Autoconf cannot support ":" in the directory name.

Both "=" and "-" can work, which would you suggest to use?
I've not observed "-" or "=" in DMI fields till now, and I guess "=" is 
less likely to be used by vendors.

Thanks
Mengdong