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

[Dmitry Baryshkov]

On 22/06/2022 00:16, Bjorn Helgaas wrote:
> On Tue, Jun 21, 2022 at 11:45:12PM +0300, Dmitry Baryshkov wrote:
> > On Tue, 21 Jun 2022 at 23:32, Bjorn Helgaas <helgaas@xxxxxxxxxx> 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().
> > >
> > > Is the fact that IPQ8074 has both a Gen2 and a Gen3 port relevant to
> > > this patch?  I don't see the connection.
> > >
> > > I see that qcom_pcie_host_init() does:
> > >
> > >    qcom_pcie_host_init
> > >      pcie->cfg->ops->init(pcie)
> > >      phy_power_on(pcie->phy)
> > >      pcie->cfg->ops->post_init(pcie)
> > >
> > > and that you're moving DBI register accesses from
> > > qcom_pcie_init_2_3_3() to qcom_pcie_post_init_2_3_3().
> > >
> > > 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?
> > >
> > > Whatever the reason, I think the DBI accesses should be done
> > > consistently in .post_init().  I see that Dmitry's previous patches
> > > removed all those .post_init() functions, but I think the consistency
> > > is worth having.
> > >
> > > Perhaps we could reorder the patches so this patch comes first, moves
> > > the DBI accesses into .post_init(), then Dmitry's patches could be
> > > rebased on top to drop the clock handling?
> >
> > I don't think there is a need to reorder patches. My patches do not
> > remove support for post_init(), they drop the callbacks code. Thus one
> > can reinstate necessary code back.
>
> There's not a *need* to reorder them, but I think it would make the
> patches smaller and more readable because we wouldn't be removing and
> then re-adding the functions.

Ack. I'm fine then with rebasing my patches on top of Robert's patchset. 
I'll send the next revision after getting this patchset into the form.

--
With best wishes
Dmitry