On Sat, 30 Jan 2021 at 11:04, Yassine Oudjana <y.oudjana@xxxxxxxxxxxxxx> wrote: > > 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. As a quick hack, you can try using this power domain for the pci_phy (see my v1). Rob declined this approach, but it is useful to check if QCA6174 wakes up properly and deferring PCIe probing till the chip is powered up. -- With best wishes Dmitry
