Re: [RFC PATCH 03/14] ASoC: qcom: Add USB backend ASoC driver for Q6
From: Wesley Cheng
Date: Tue Dec 27 2022 - 16:11:03 EST
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