Re: [PATCH v35 00/31] Introduce QC USB SND audio offloading support

[Stephan Gerhold]

On Tue, Mar 04, 2025 at 02:46:28PM -0800, Wesley Cheng wrote:
> On 3/4/2025 12:22 AM, Stephan Gerhold wrote:
> > On Mon, Mar 03, 2025 at 06:39:52PM -0800, Wesley Cheng wrote:
> >> On 2/19/2025 3:24 AM, Stephan Gerhold wrote:
> >>> On Tue, Feb 18, 2025 at 04:47:23PM -0800, Wesley Cheng wrote:
> >>>> Requesting to see if we can get some Acked-By tags, and merge on usb-next.
> >>>>
> >>>> Several Qualcomm based chipsets can support USB audio offloading to a
> >>>> dedicated audio DSP, which can take over issuing transfers to the USB
> >>>> host controller.  The intention is to reduce the load on the main
> >>>> processors in the SoC, and allow them to be placed into lower power modes.
> >>>> There are several parts to this design:
> >>>>   1. Adding ASoC binding layer
> >>>>   2. Create a USB backend for Q6DSP
> >>>>   3. Introduce XHCI interrupter support
> >>>>   4. Create vendor ops for the USB SND driver
> >>>>
> >>>>       USB                          |            ASoC
> >>>> --------------------------------------------------------------------
> >>>>                                    |  _________________________
> >>>>                                    | |sm8250 platform card     |
> >>>>                                    | |_________________________|
> >>>>                                    |         |           |
> >>>>                                    |      ___V____   ____V____
> >>>>                                    |     |Q6USB   | |Q6AFE    |
> >>>> |     |"codec" | |"cpu"    |
> >>>>                                    |     |________| |_________|
> >>>>                                    |         ^  ^        ^
> >>>>                                    |         |  |________|
> >>>>                                    |      ___V____    |
> >>>>                                    |     |SOC-USB |   |
> >>>>    ________       ________               |        |   |
> >>>>   |USB SND |<--->|QC offld|<------------>|________|   |
> >>>>   |(card.c)|     |        |<----------                |
> >>>>   |________|     |________|___     | |                |
> >>>>       ^               ^       |    | |    ____________V_________
> >>>>       |               |       |    | |   |APR/GLINK             |
> >>>>    __ V_______________V_____  |    | |   |______________________|
> >>>>   |USB SND (endpoint.c)     | |    | |              ^
> >>>>   |_________________________| |    | |              |
> >>>>               ^               |    | |   ___________V___________
> >>>>               |               |    | |->|audio DSP              |
> >>>>    ___________V_____________  |    |    |_______________________|
> >>>>   |XHCI HCD                 |<-    |
> >>>>   |_________________________|      |
> >>>>
> >>>
> >>> As I noted on v34 [1], this version is still missing instructions and
> >>> changes needed for testing this series. The device tree changes don't
> >>> need to be part of the same series, but there should be at least a link
> >>> provided to give other people the chance to provide Tested-by tags.
> >>>
> >>> IMO we shouldn't merge this series without those instructions, otherwise
> >>> we risk that this just ends up being dead code that no one can use.
> >>>
> >>> Can you please share the device tree changes for a board upstream and
> >>> any other changes needed to be able to test this series? E.g. for
> >>> sm8250-mtp.dts, based on the examples in your cover letter.
> >>>
> >>
> >> To clarify I'm testing this on sm8350 in recent times, but utilizing sm8250
> >> definitions for the ASoC platform card, as the platform sound card is more
> >> or less the same between the two SoCs.  Back
> >> when I started this series, sm8350 was missing a bunch of dependent
> >> components, such as aDSP not being loaded, and missing platform sound card
> >> definition, so I had to define and enable those on my own, which required a
> >> slew of new DT nodes, hence why it wasn't as straight forward to include
> >> the DT definitions yet for sm8350.  Not thinking that this series would
> >> take as long as it did, I was planning on separating out the DT changes in
> >> a different series to enable offloading for the devices I have tested with.
> >> (sm8150, sm8250 and sm8350)
> >>
> >> There's still a pretty big chunk of dependencies missing from sm8350, so
> >> those would also be handled in the follow up DT submission.  For now, its a
> >> much bigger hurdle to get the main/functional changes in, and that was
> >> taking a significant amount of time from my end to manage.
> >>
> >> If you want, I can give you the changes I have offline to enable this for
> >> sm8350, since I haven't spent time formatting/prepping the changes for
> >> submission yet.
> >>
> > 
> > Can you push it to a public branch somewhere (e.g. on CodeLinaro)? I was
> > talking to some people from the community about testing this on some of
> > the smartphones we have in upstream, so it wouldn't help if I just have
> > the changes privately.
> 
> Which CLO project/branch did you want me to push it to?  Sorry, I haven't
> worked too much with the CLO open branches.  I have an account though.
> 

Any project/branch is fine for me, I suggested CLO only because I
assumed you already have an account there.

You should be able to create a personal project and push it there. You
could also use the fork button on
https://git.codelinaro.org/linaro/linux/kernel/torvalds/linux to avoid
having to push the full history yourself. It should result in a project
similar to mine: https://git.codelinaro.org/stephan.gerhold/linux

Thanks,
Stephan