On Thu, Aug 5, 2021 at 1:58 AM Mauro Carvalho Chehab
[off-list ref] wrote:

Em Thu, 5 Aug 2021 09:46:12 +0200
Mauro Carvalho Chehab [off-list ref] escreveu:

quoted

Em Wed, 4 Aug 2021 10:28:53 -0600
Rob Herring [off-list ref] escreveu:

quoted

On Wed, Aug 04, 2021 at 08:50:45AM +0200, Mauro Carvalho Chehab wrote:

quoted

Em Tue, 3 Aug 2021 16:11:42 -0600
Rob Herring [off-list ref] escreveu:

quoted

On Mon, Aug 2, 2021 at 10:39 PM Mauro Carvalho Chehab
[off-list ref] wrote:

quoted

Hi Rob,

That's the third version of the DT bindings for Kirin 970 PCIE and its
corresponding PHY.

It is identical to v2, except by:
        -          pcie@7,0 { // Lane 7: Ethernet
        +          pcie@7,0 { // Lane 6: Ethernet

Can you check whether you have DT node links in sysfs for the PCI
devices? If you don't, then something is wrong still in the topology
or the PCI core is failing to set the DT node pointer in struct
device. Though you don't rely on that currently, we want the topology
to match. It's possible this never worked on arm/arm64 as mainly
powerpc relied on this.

I'd like some way to validate the DT matches the PCI topology. We
could have a tool that generates the DT structure based on the PCI
topology.

The of_node node link is on those places:

  $ find /sys/devices/platform/soc/f4000000.pcie/ -name of_node
  /sys/devices/platform/soc/f4000000.pcie/of_node
  /sys/devices/platform/soc/f4000000.pcie/pci0000:00/0000:00:00.0/of_node
  /sys/devices/platform/soc/f4000000.pcie/pci0000:00/0000:00:00.0/pci_bus/0000:01/of_node
  /sys/devices/platform/soc/f4000000.pcie/pci0000:00/pci_bus/0000:00/of_node

Looks like we're missing some...

It's not immediately obvious to me what's wrong here. Only the root
bus is getting it's DT node set. The relevant code is pci_scan_device(),
pci_set_of_node() and pci_set_bus_of_node(). Give me a few days to try
to reproduce and debug it.

I added a printk on both pci_set_*of_node() functions:

      [    4.872991]  (null): pci_set_bus_of_node: of_node: /soc/pcie@f4000000
      [    4.913806]  (null): pci_set_of_node: of_node: /soc/pcie@f4000000
      [    4.978102] pci_bus 0000:01: pci_set_bus_of_node: of_node: /soc/pcie@f4000000/pcie@0,0
      [    4.990622]  (null): pci_set_of_node: of_node: /soc/pcie@f4000000/pcie@0,0
      [    5.052383] pci_bus 0000:02: pci_set_bus_of_node: of_node: (null)
      [    5.059263]  (null): pci_set_of_node: of_node: (null)
      [    5.085552]  (null): pci_set_of_node: of_node: (null)
      [    5.112073]  (null): pci_set_of_node: of_node: (null)
      [    5.138320]  (null): pci_set_of_node: of_node: (null)
      [    5.164673]  (null): pci_set_of_node: of_node: (null)
      [    5.233759] pci_bus 0000:03: pci_set_bus_of_node: of_node: (null)
      [    5.240539]  (null): pci_set_of_node: of_node: (null)
      [    5.310545] pci_bus 0000:04: pci_set_bus_of_node: of_node: (null)
      [    5.324719] pci_bus 0000:05: pci_set_bus_of_node: of_node: (null)
      [    5.338914] pci_bus 0000:06: pci_set_bus_of_node: of_node: (null)
      [    5.345516]  (null): pci_set_of_node: of_node: (null)
      [    5.415795] pci_bus 0000:07: pci_set_bus_of_node: of_node: (null)

The enclosed patch makes the above a clearer:

        [    4.800975]  (null): pci_set_bus_of_node: of_node: /soc/pcie@f4000000
        [    4.855983] pci 0000:00:00.0: pci_set_of_node: of_node: /soc/pcie@f4000000
        [    4.879169] pci_bus 0000:01: pci_set_bus_of_node: of_node: /soc/pcie@f4000000/pcie@0,0
        [    4.900602] pci 0000:01:00.0: pci_set_of_node: of_node: /soc/pcie@f4000000/pcie@0,0
        [    4.953086] pci_bus 0000:02: pci_set_bus_of_node: of_node: (null)

I believe the issue is we need another bridge node in the DT
hierarchy. What we have is:

Bus 0 is node /soc/pcie@f4000000
Bus 1 is device 0 on bus 0 is node /soc/pcie@f4000000/pcie@0,0
Bus 2 is device 0 on bus 1 in node ... whoops, there's no device 0
under /soc/pcie@f4000000/pcie@0,0

So we need the hierarchy to be: /soc/pcie@f4000000/pcie@0/pcie@0/pcie@{1,5,7}

Rob