Re: [PATCH v3 01/10] ARM: tegra: Set the sound card model that alsaucm expects

From: Tomeu Vizoso
Date: Tue Feb 03 2015 - 08:13:58 EST


On 2 February 2015 at 22:08, Stephen Warren <swarren@xxxxxxxxxxxxx> wrote:
> On 01/28/2015 03:50 AM, Tomeu Vizoso wrote:
>>
>> Patches are on its way to add a config file to alsaucm for the Nyan
>> boards. Use the same card ID that alsaucm will expect.
>
>
>> diff --git a/arch/arm/boot/dts/tegra124-nyan-big.dts
>> b/arch/arm/boot/dts/tegra124-nyan-big.dts
>
>
>> sound {
>> - compatible = "nvidia,tegra-audio-max98090-nyan-big",
>> + compatible = "nvidia,tegra-audio-max98090-nyan",
>> "nvidia,tegra-audio-max98090";
>
>
> I'm not convinced that removing the board-specific compatible value is a
> great idea. What if we find we need to distinguish between different boards
> that use this same binding in the future. That situation is exactly why we
> have board-/SoC-specific values in compatible even if we don't immediately
> use them.

I understand the need of naming each component variant so they can be
distinguished in the future, but in this case it's the exact same hw.

>> - nvidia,model = "Acer Chromebook 13";
>> + nvidia,model = "GoogleNyan";
>
>
> I believe this also technically breaks ABI, since some user-space tools use
> the model to look up saved state. Can we not leave this as is, and just have
> the UCM files know about both names?

Well, "A13" isn't a great card id. Given that there's no users yet, I
would prefer to take this chance to put a sane value in there. Btw,
alsa-lib has now a UCM config for this and it uses the GoogleNyan card
id (has been picked up already by OpenSUSE).

So in this case, I think it would be good to change the card id now
before people start to actually use it.

Regards,

Tomeu

> Aside from that, I think the series looks OK at a quick glance.
>
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