This patchset provides an optimization that result in significant power savings on Intel HDAudio platforms using SOF (Sound Open Firmware). We previously prevented the Intel DSP from enabling the DMI_L1 capability to work-around issues with pause on capture streams. It turns out that this also prevented the platform from entering high C states in full-duplex usages such as videoconferencing - a rather basic use case since the start of the pandemic. The support for pause_push/release was already a bit controversial for Intel platforms, in theory platforms should only enable PAUSE if they can resume on the same sample, which is not the case on any Intel platform. With this patchset, when the user enables DMI L1 via a kernel parameter, the PAUSE support is disabled for capture streams. A kernel parameter is far from ideal but it's a placeholder until we have an API to negotiate capabilities between applications and driver, and it's far less confusing than a Kconfig option. Changes since v1: Removal of SPIB support since it may conflict with Takashi's memalloc changes. These SPIB changes will be provided after rebase. Addition of one cleanup for cppcheck warning Move all changes to intel/ directory, no changes in shared code Flipped the logic: the selection of DMI L1 disables PAUSE Pierre-Louis Bossart (4): ASoC: SOF: Intel: Kconfig: clarify DMI L1 option description ASoC: SOF: Intel: hda-stream: remove always true condition ASoC: SOF: Intel: simplify logic for DMI_L1 handling ASoC: SOF: Intel: make DMI L1 selection more robust sound/soc/sof/intel/Kconfig | 10 ---------- sound/soc/sof/intel/hda-pcm.c | 16 ++++++++++++++-- sound/soc/sof/intel/hda-stream.c | 11 +++++------ 3 files changed, 19 insertions(+), 18 deletions(-) -- 2.25.1
