Hi Stephan, On 3/25/2025 4:35 AM, Stephan Gerhold wrote: > On Tue, Mar 18, 2025 at 05:51:40PM -0700, Wesley Cheng wrote: >> In order to allow userspace/applications know about USB offloading status, >> expose a sound kcontrol that fetches information about which sound card >> and PCM index the USB device is mapped to for supporting offloading. In >> the USB audio offloading framework, the ASoC BE DAI link is the entity >> responsible for registering to the SOC USB layer. >> >> It is expected for the USB SND offloading driver to add the kcontrol to the >> sound card associated with the USB audio device. An example output would >> look like: >> >> tinymix -D 1 get 'USB Offload Playback Route PCM#0' >> -1, -1 (range -1->255) >> >> This example signifies that there is no mapped ASoC path available for the >> USB SND device. >> >> tinymix -D 1 get 'USB Offload Playback Route PCM#0' >> 0, 0 (range -1->255) >> >> This example signifies that the offload path is available over ASoC sound >> card index#0 and PCM device#0. >> >> The USB offload kcontrol will be added in addition to the existing >> kcontrols identified by the USB SND mixer. The kcontrols used to modify >> the USB audio device specific parameters are still valid and expected to be >> used. These parameters are not mirrored to the ASoC subsystem. >> >> Signed-off-by: Wesley Cheng <quic_wcheng@xxxxxxxxxxx> >> --- >> sound/usb/Kconfig | 10 ++ >> sound/usb/qcom/Makefile | 4 + >> sound/usb/qcom/mixer_usb_offload.c | 158 +++++++++++++++++++++++++++++ >> sound/usb/qcom/mixer_usb_offload.h | 17 ++++ >> sound/usb/qcom/qc_audio_offload.c | 2 + >> 5 files changed, 191 insertions(+) >> create mode 100644 sound/usb/qcom/mixer_usb_offload.c >> create mode 100644 sound/usb/qcom/mixer_usb_offload.h >> >> diff --git a/sound/usb/Kconfig b/sound/usb/Kconfig >> index 6daa551738da..7d8833945711 100644 >> --- a/sound/usb/Kconfig >> +++ b/sound/usb/Kconfig >> @@ -176,9 +176,19 @@ config SND_BCD2000 >> To compile this driver as a module, choose M here: the module >> will be called snd-bcd2000. >> >> +config SND_USB_QC_OFFLOAD_MIXER >> + tristate "Qualcomm USB Audio Offload mixer control" > > This looks like a "bool" and not a "tristate", since the ifneq in the > Makefile below ignores whether this is a "y" or "m". > Yeah, let me fix this. >> + help >> + Say Y to enable the Qualcomm USB audio offloading mixer controls. >> + This exposes an USB offload capable kcontrol to signal to >> + applications about which platform sound card can support USB >> + audio offload. The returning values specify the mapped ASoC card >> + and PCM device the USB audio device is associated to. >> + >> config SND_USB_AUDIO_QMI >> tristate "Qualcomm Audio Offload driver" >> depends on QCOM_QMI_HELPERS && SND_USB_AUDIO && USB_XHCI_SIDEBAND && SND_SOC_USB >> + select SND_USB_OFFLOAD_MIXER > > And I think "SND_USB_OFFLOAD_MIXER" (without _QC suffix) doesn't exist > anymore after v30? I see there was some discussion around that there. > Is this supposed to be "select SND_USB_QC_OFFLOAD_MIXER"? > > If yes, isn't this option always selected if SND_USB_AUDIO_QMI is > enabled? In that case you could just drop the config option... > Will address this as well. Thanks Wesley Cheng
