[PATCH v2] PCI: dw-rockchip: Enable async probe by default

[Niklas Cassel]

On Fri, Jan 03, 2025 at 08:10:17PM +0530, Anand Moon wrote:
> Hi Niklas
> 
> On Fri, 3 Jan 2025 at 19:55, Niklas Cassel <cassel at kernel.org> wrote:
> >
> > Hello Anand,
> >
> > On Fri, Jan 03, 2025 at 07:24:07PM +0530, Anand Moon wrote:
> > >
> > > Thanks for testing this patch.
> > >
> > > This patch should have been tested on hardware that includes all the
> > > relevant controllers,
> > > such as PCI 2.0, PCI 3.0, and the SATA controller.
> > > I will test this patch again on all the Radxa devices I have.
> > >
> > > This patch's dependency lies in deferring the probe until the PHY
> > > controller initializes.
> > >
> > > CONFIG_PHY_ROCKCHIP_NANENG_COMBO_PHY=m
> >
> >
> > Note that the splat, as reported in this thread, and in:
> > https://lore.kernel.org/netdev/20250101235122.704012-1-francesco@valla.it/T/
> >
> > is related to the network PHY (CONFIG_REALTEK_PHY) on the RTL8125 NIC,
> > which is connected to one of the PCIe Gen2 controllers, not the PCIe PHY
> > on the PCIe controller (CONFIG_PHY_ROCKCHIP_NANENG_COMBO_PHY) itself.
> >
> > For the record, I run with all the relevant drivers as built-in:
> > CONFIG_PCIE_ROCKCHIP_DW_HOST=y
> > CONFIG_PHY_ROCKCHIP_NANENG_COMBO_PHY=y (for the PCIe Gen2 controllers)
> > CONFIG_PHY_ROCKCHIP_SNPS_PCIE3=y (for the PCIe Gen3 controllers)
> > CONFIG_R8169=y
> > CONFIG_REALTEK_PHY=y
> >
> >
> > >
> > > To my surprise, we have not enabled mdio on Rock-5B boards.
> > > can you check if these changes work on your end?
> >
> > I think these changes are wrong, at least for rock5b.
> 
> We need to enable the GMAC PHY and reset it using the proper GPIO pin
> (PCIE_PERST_L).
> Please refer to the schematic for more details.

The PERST# GPIO is already asserted + deasserted from the PCIe Root Complex
(host) driver:
https://github.com/torvalds/linux/blob/v6.13-rc5/drivers/pci/controller/dwc/pcie-dw-rockchip.c#L191-L206

which will cause the endpoint device (a RTL8125 NIC in this case)
to be reset during bootup.


Kind regards,
Niklas