Re: [PATCH v2] PCI: qcom: fix IPQ8074 Gen2 support

From: Johan Hovold
Date: Wed Jun 22 2022 - 03:33:31 EST


On Wed, Jun 22, 2022 at 08:49:20AM +0200, Johan Hovold wrote:
> On Tue, Jun 21, 2022 at 03:32:11PM -0500, Bjorn Helgaas wrote:
> > On Tue, Jun 21, 2022 at 01:23:30PM +0200, Robert Marko wrote:
> > > IPQ8074 has one Gen2 and one Gen3 port, currently the Gen2 port will
> > > cause the system to hang as its using DBI registers in the .init
> > > and those are only accesible after phy_power_on().

> > But I also see DBI register accesses in other .init() functions:
> >
> > qcom_pcie_init_2_1_0
> > qcom_pcie_init_1_0_0 (oddly out of order)
> > qcom_pcie_init_2_3_2
> > qcom_pcie_init_2_4_0
> >
> > Why do these accesses not need to be moved? I assume it's because
> > pcie->phy is an optional PHY and phy_power_on() does nothing on those
> > controllers?
>
> At least the QMP PHY driver does not implement the PHY power_on op and
> instead fires everything up already at phy_init(). That may explain the
> difference in behaviour here.

Or maybe not, IPQ8074 appears to be using the same PHY driver.

Johan