- Need to port Intel's 5.0 kernel branch to (Disco) oem-kernel for DMIC (digital MIC) support in some OEM platforms
To support digital mic which is directly connected to PCH, Intel recommend Dell
and us to use sound:asoc:sof driver. This driver is under upstreaming, so far,
only part of the driver is merged to ASoC's tree.
Dell already have a couple of laptop models which connect the dmic to PCH, and
Dell pushed Intel to prepare a workable sof driver under v5.0 branch, and
pused us to integrate this driver, then the dmic can work on those laptop
models. (Lenovo also have 2 laptops which has this dmic design)
According to Intel's estimation, the whole sof driver can't be upstreamed in a
short of period. So Intel provided a branch which contains some upstreamed
patches and some not-yet patches.
Intel tested the provided branch, and looks the testing result is good.
PLease access https://people.canonical.com/~hwang4/sof-doc/ to get the testing
result.
I also made a simple test after oem-d merged those patches, I didn't find
big issues too.
There are some patches which touched the common code or the code of other
subsystems. Intel said it is safe, and I also looked at those patches, I also
think it is safe. But because there are too many changes, let us put this driver
into the OEM-D kernel, this driver will not merge to generic kernel.
[Impact]
Our OEM project need to enable a couple of laptops which connect the dmic
directly to the PCH, there is no driver for this design in the linux kernel,
so we need to integrate Intel's sof driver.
[Fix]
Intel provided a sof driver tree based on v5.0, it is for oem-d kernel
[Test Case]
Intel tested the audio functions, the testing result is good.
https://people.canonical.com/~hwang4/sof-doc/Beta%20Test%20Report%20-%20Dell%20Mantis%20(CML)%20%20-%20Apr%2030.pdf
I also made a simple test, speaker, headphone, dmic and headset-mic
worked.
[Regression Risk]
Low. So far both Intel side and I have not found any regression introduced by this
patchset, and to lower the risk, we only integrate the driver to oem-d kernel,
and after the image is ready, the oem project will perform the full-range test.
note; technically, it's 'OEM-OSP1-B', disco doesn't have an oem kernel of it's own ;)