lkml.org 
[lkml]   [2023]   [Sep]   [11]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
Date
SubjectRe: [PATCH v5 18/32] sound: usb: Introduce QC USB SND offloading support
From
Hi Takashi,

On 9/7/2023 8:51 AM, Takashi Iwai wrote:
> On Tue, 29 Aug 2023 23:06:43 +0200,
> 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.
>>
>> Audio offloading is initiated with the following sequence:
>> 1. Userspace configures to route audio playback to USB backend and starts
>> playback on the platform soundcard.
>> 2. The Q6DSP AFE will communicate to the audio DSP to start the USB AFE
>> port.
>> 3. This results in a QMI packet with a STREAM enable command.
>> 4. The QC audio offload driver will fetch the required resources, and pass
>> this information as part of the QMI response to the STREAM enable command.
>> 5. Once the QMI response is received the audio DSP will start queuing data
>> on the USB bus.
>>
>> Signed-off-by: Wesley Cheng <quic_wcheng@quicinc.com>
>> ---
>> sound/usb/Kconfig | 15 +
>> sound/usb/Makefile | 2 +-
>> sound/usb/qcom/Makefile | 2 +
>> sound/usb/qcom/qc_audio_offload.c | 1813 +++++++++++++++++++++++++++++
>> 4 files changed, 1831 insertions(+), 1 deletion(-)
>> create mode 100644 sound/usb/qcom/Makefile
>> create mode 100644 sound/usb/qcom/qc_audio_offload.c
>>
>> diff --git a/sound/usb/Kconfig b/sound/usb/Kconfig
>> index 4a9569a3a39a..da5838656baa 100644
>> --- a/sound/usb/Kconfig
>> +++ b/sound/usb/Kconfig
>> @@ -176,6 +176,21 @@ config SND_BCD2000
>> To compile this driver as a module, choose M here: the module
>> will be called snd-bcd2000.
>>
>> +config QC_USB_AUDIO_OFFLOAD
>
> Keep SND_ prefix for consistency. And, at best, align with the module
> name.
>
>> + tristate "Qualcomm Audio Offload driver"
>> + depends on QCOM_QMI_HELPERS && SND_USB_AUDIO && USB_XHCI_SIDEBAND
>> + select SND_PCM
>> + help
>> + Say Y here to enable the Qualcomm USB audio offloading feature.
>> +
>> + This module sets up the required QMI stream enable/disable
>> + responses to requests generated by the audio DSP. It passes the
>> + USB transfer resource references, so that the audio DSP can issue
>> + USB transfers to the host controller.
>> +
>> + To compile this driver as a module, choose M here: the module
>> + will be called qc-audio-offload.
>
> Hmm, you renamed it differently, no? In the below:
>
>> --- /dev/null
>> +++ b/sound/usb/qcom/Makefile
>> @@ -0,0 +1,2 @@
>> +snd-usb-audio-qmi-objs := usb_audio_qmi_v01.o qc_audio_offload.o
>> +obj-$(CONFIG_QC_USB_AUDIO_OFFLOAD) += snd-usb-audio-qmi.o
>
> ... it's called snd-usb-audio-qmi.
>

Will fix this, thanks.

Thanks
Wesley Cheng

\
 
 \ /
  Last update: 2023-09-12 00:01    [W:0.078 / U:1.728 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site