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Date:   Tue, 27 Dec 2022 13:06:35 -0800
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Subject: Re: [RFC PATCH 03/14] ASoC: qcom: Add USB backend ASoC driver for Q6
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To:     Mark Brown <broonie@kernel.org>,
        Greg KH <gregkh@linuxfoundation.org>
CC:     <srinivas.kandagatla@linaro.org>, <mathias.nyman@intel.com>,
        <perex@perex.cz>, <lgirdwood@gmail.com>, <andersson@kernel.org>,
        <krzysztof.kozlowski+dt@linaro.org>, <Thinh.Nguyen@synopsys.com>,
        <bgoswami@quicinc.com>, <tiwai@suse.com>, <robh+dt@kernel.org>,
        <agross@kernel.org>, <linux-kernel@vger.kernel.org>,
        <linux-arm-msm@vger.kernel.org>, <alsa-devel@alsa-project.org>,
        <devicetree@vger.kernel.org>, <linux-usb@vger.kernel.org>,
        <quic_jackp@quicinc.com>, <quic_plai@quicinc.com>
References: <20221223233200.26089-1-quic_wcheng@quicinc.com>
 <20221223233200.26089-4-quic_wcheng@quicinc.com> <Y6bAQ8hDLkvrvjQQ@kroah.com>
 <Y6rtdy4NPfi/KOqd@sirena.org.uk> <Y6r26VfIfpE8zpPY@kroah.com>
 <Y6sLH+8nVFImL0Oo@sirena.org.uk>
From:   Wesley Cheng <quic_wcheng@quicinc.com>
In-Reply-To: <Y6sLH+8nVFImL0Oo@sirena.org.uk>
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Hi Mark/Greg,

On 12/27/2022 7:11 AM, Mark Brown wrote:
> On Tue, Dec 27, 2022 at 02:45:13PM +0100, Greg KH wrote:
>> On Tue, Dec 27, 2022 at 01:04:55PM +0000, Mark Brown wrote:
>>> On Sat, Dec 24, 2022 at 10:02:59AM +0100, Greg KH wrote:
> 
>>>>> + * Copyright (c) 2022 Qualcomm Innovation Center, Inc. All rights reserved.
> 
>>>> All of the code in this patch series is older than 2022 as I know it has
>>>> been in shipping devices for many years.  Please use the proper
>>>> copyright year to make your lawyers happy...
> 
>>> Are you *positive* about this.  Based on some preparatory discussions
>>> the Qualcomm people had with Takashi and I it seemed like this was a new
>>> version of existing concepts.  I'm sure they had something already but
>>> it's not obvious to me that they're just posting the same code.
> 
>> I thought that this same code has been shipping in devices for a few
>> years now in the last few Samsung phone models.  Is this not the same
>> code that is in those devices?
> 
>> If not, why not, what happened to that codebase that makes it not worthy
>> of being submitted upstream?
> 
> I don't specifically know anything about that code but I'd expect that
> for out of tree code breaking new ground like this there'd be a strong
> likelyhood that there'd be design level issues and that's what the pre
> submission discussions were all about - how to fit the concept into the
> kernel subsystems in a way that might be maintainable.  There's also
> been the whole transition to their new DSP firmware going on.  It's
> possible that what was shipped was implemented in the same way with the
> same code but I'd not assume that this is the case without actually
> comparing the two.

It's correct that all the ASoC related patches are new, and didn't exist 
previously in QC products.  It is due to the fact that Android has a 
different ALSA userspace concept which allowed for a lot of the Q6 audio 
front end (AFE) communication to be done from userspace, I believe. 
This is the reason that we had to introduce this new ASoC based design.

I can't comment much more about the Android ALSA design, maybe @Patrick 
Lai can.

Thanks
Wesley Cheng