Rander Wang

Could you give a full picture of solution ? How to use chain dma ? How to support in topology ? How does driver do to cooperate with topology?

> @RanderWang I believe you would need the plumbing added in #3792 to test this PR? @plbossart thanks. I also tested with driver modification. The get_time_info was called by snd_sof_pcm_period_elapsed...

> @RanderWang I believe you would need the plumbing added in #3792 to test this PR? thanks. I tested with PR and the time log should be correct.

updated， thanks！

@plbossart updated for capture. One issue is that llp registger is for normal dma but HDA uses link dma, so we can't get llp info for HDA case. And in...

> @RanderWang for HDAudio the register is LPIB, you should be able to read it from the host? I will use intel HDA audio global synchronization registers, like https://github.com/thesofproject/linux/blob/topic/sof-dev/sound/pci/hda/hda_controller.c#L411-L422 ````c...

> > This should be enough @RanderWang > > ```c > /* Read Link counter */ > ll_counter_l = snd_hdac_chip_readl(azx_bus(chip), LLPCL); > ll_counter_h = snd_hdac_chip_readl(azx_bus(chip), LLPCU); > ``` > >...

> @RanderWang if you find a way to add this capability in a backwards-compatible manner that would be good indeed. Changes would probably have to be reviewed by @lgirdwood @mmaka1...

update HDA support since fw doesn't support llp info for HDA. Read wclk and llp in host MMIO space.

> Sorry for the late comments to some topics, but looking at this series again, I found some new concerns. A few of the functions have grown really big and...