Messages in this thread | | | Date | Thu, 5 Jan 2023 17:06:00 -0800 | Subject | Re: [RFC PATCH 09/14] sound: usb: Introduce QC USB SND offloading support | From | Wesley Cheng <> |
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Hi Pierre,
On 1/4/2023 3:51 PM, Pierre-Louis Bossart wrote: > > > On 12/23/22 17:31, Wesley Cheng wrote: >> Several Qualcomm SoCs have a dedicated audio DSP, which has the ability to >> support USB sound devices. This vendor driver will implement the required >> handshaking with the DSP, in order to pass along required resources that >> will be utilized by the DSP's USB SW. The communication channel used for >> this handshaking will be using the QMI protocol. Required resources >> include: >> - Allocated secondary event ring address >> - EP transfer ring address >> - Interrupter number >> >> The above information will allow for the audio DSP to execute USB transfers >> over the USB bus. It will also be able to support devices that have an >> implicit feedback and sync endpoint as well. Offloading these data >> transfers will allow the main/applications processor to enter lower CPU >> power modes, and sustain a longer duration in those modes. > > Are you suggesting that the entire feedback loop be handled in the DSP? > It's not clear what "Offloading these data transfers" refers to, the > data part or the feedback path? >
Yes, as mentioned in the cover letter response, we'll handle the feedback endpoints. (feedback eps are part of the audio data interface)
> Comments are almost inexistent in this patch so it's hard to figure out > what it really does. >
OK, will add some more comments.
Thanks Wesley Cheng
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