On Tue, 31 Jul 2018 14:28:41 +0200, Jorge Sanjuan wrote: > > This is what's new in this v3: > - Add proper SPDX identifier for new source file. > - Add delay unit in comment for BADD inferred recovery > times and specify the actual delay time for them. > - Suspend the usb stream *after* alsa has supended its stuff. > - Make sure Power State changes to D0 happen *before* stream > format is set. > - Try to set the Power State to D0 on .prepare callback too as > recovery from suspend state doesn't need .hw_params call. > > This patchset adds support for UAC3 Power Domains. This feature > of the USB audio class 3 allows the host to notify the device > what it is making use of so power comsumption can be optimized. > > This proposal implements this feature for Power Domains > that include an Input/Output Terminal associated to an > audio Streaming interface. This is the main usage of this > feature according to the spec. For that reason, the logic > for the Power Domain state change has been implemented > within the ALSA PCMs logic and the suspend/resume callbacks > of the usb_driver. The behaviour would be as follows: > > * Power Domain State D0: A Power Domain will reach this state > only when the audio substream associated to that domain is > being used (i,e. Audio playback/capture is happening). > * Power Domain State D1: This is the Idle state where the driver > is going to always want to be in order to reduce power > consumption. > * Power Domain State D2: This state is only set when the usb driver > asumes the device is not going to be used anymore and hence, it > wont care about getting any interrupts from the device. This > will only happen when power level is set to "auto" in sysfs > so the usb driver gets suspended when the interfaces are not in use. > > NOTE: The way this has been implemented will always try to put the > Power Domain in state D1 if the Power Domain exists. The patch > "ALSA: usb-audio: Operate UAC3 Power Domains in PCM callbacks" > puts the logic for doing so inside the PCM's logic. Something to > improve on that is to also tie up those D1<->D0 state changes > to runtime PM maybe. > > > Jorge Sanjuan (4): > ALSA: usb-audio: Initial Power Domain support > ALSA: usb-audio: AudioStreaming Power Domain parsing > ALSA: usb-audio: Add UAC3 Power Domains to suspend/resume > ALSA: usb-audio: Operate UAC3 Power Domains in PCM callbacks Now I merge all these four patches. Thanks! Takashi _______________________________________________ Alsa-devel mailing list Alsa-devel@xxxxxxxxxxxxxxxx http://mailman.alsa-project.org/mailman/listinfo/alsa-devel
