Re: [PATCH v4 4/5] dm: pci: Assign controller device node to root bridge

From: Nicolas Saenz Julienne
Date: Wed Jun 17 2020 - 15:15:27 EST


On Tue, 2020-06-16 at 17:31 -0600, Simon Glass wrote:
> Hi Nicolas,
>
> On Tue, 16 Jun 2020 at 08:09, Nicolas Saenz Julienne
> <nsaenzjulienne@xxxxxxx> wrote:
> > On Tue, 2020-06-16 at 07:43 -0600, Simon Glass wrote:
> > > Hi Nicolas,
> > >
> > > On Fri, 12 Jun 2020 at 10:47, Nicolas Saenz Julienne
> > > <nsaenzjulienne@xxxxxxx> wrote:
> > > > There is no distinction in DT between the PCI controller device and the
> > > > root bridge, whereas such distinction exists from dm's perspective. Make
> > > > sure the root bridge ofnode is assigned to the controller's platform
> > > > device node.
> > > >
> > > > This permits setups like this to work correctly:
> > > >
> > > > pcie {
> > > > compatible = "...";
> > > > ...
> > > > dev {
> > > > reg = <0 0 0 0 0>;
> > > > ...
> > > > };
> > > > };
> > > >
> > > > Without this the dev node is assigned to the root bridge and the
> > > > actual device search starts one level lower than expected.
> > > >
> > > > Signed-off-by: Nicolas Saenz Julienne <nsaenzjulienne@xxxxxxx>
> > > > ---
> > > > drivers/pci/pci-uclass.c | 15 ++++++++++++++-
> > > > 1 file changed, 14 insertions(+), 1 deletion(-)
> > >
> > > Can you update the tests to handle this case please?
> >
> > I'd be glad to, but I'm not familiar with the test FW in u-booy, coud give
> > me
> > some pointers on where/how to test this?
> >
>
> Yes it is at test/dm/pci.c and the device tree is test.dts
>
> 'make qcheck' to run all tests. To run one test, build for sandbox and
> then something like
>
> u-boot -T -c "ut dm pci_swapcase"
>
> for example.
>
> You can perhaps use an existing PCI controller in test.dts but feel
> free to add one more if you need it for your test. Make sure that you
> don't break other tests.

Thanks for the info.

Actually adding the tests made me doubleguess myself, and now I'm pretty sure
that what I shoudl've done in DT is the following:

&pcie0 {
pci@0 {
#address-cells = <3>;
#size-cells = <2>;
ranges;

reg = <0 0 0 0 0>;

usb@1,0 {
reg = <0x10000 0 0 0 0>;
resets = <&reset RASPBERRYPI_FIRMWARE_RESET_ID_USB>;
};
};
};


(with "lspci -tv": [0000:00]---00.0-[01]----00.0 VIA Technologies, Inc. VL805 USB 3.0 Host Controller)

With this the patch above isn't needed, which is great.

I'll send this to upstream Linux just to get a confirmation this is correct,
although if you have any comments it'll be appreciated.

Regards,
Nicolas

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