Re: [PATCH v2 3/5] pcie-qcom: provide a way to power up qca6390 chip on RB5 platform

[Yassine Oudjana]

On Thu, Jan 28, 2021 at 11:52 AM Dmitry Baryshkov
<dmitry.baryshkov@xxxxxxxxxx> wrote:
>
> Some Qualcomm platforms require to power up an external device before
> probing the PCI bus. E.g. on RB5 platform the QCA6390 WiFi/BT chip needs
> to be powered up before PCIe0 bus is probed. Add a quirk to the
> respective PCIe root bridge to attach to the power domain if one is
> required, so that the QCA chip is started before scanning the PCIe bus.

I'm lead to believe that this is also needed for QCA6174. I tried taking
the driver you wrote and changing regulators to match the ones used by QCA6174,
but I found that it gets probed after PCIe, which makes it get -EPROBE_DEFER
when it tries to attach to the power domain, which it doesn't handle it and
just proceeds to scan the bus and not find the chip as usual.