Re: [PATCH 0/4] Fix RP1 DeviceTree hierarchy and drop overlay support
From: Florian Fainelli
Date: Thu Dec 18 2025 - 14:11:07 EST
On 12/18/25 11:09, Andrea della Porta wrote:
The current RP1 implementation is plagued by several issues, as follows:
- the node name for RP1 is too specific and should be generic instead
(see [1]).
- the fully defined DTS has its PCI hierarchy wrongly described. There
should be a PCI root port between the root complex and the endpoint
(see [1]).
- since CONFIG_PCI_DYNAMIC_OF_NODES can be dropped in the future
becoming an automatically enabled feature, it would be wise to not
depend on it (see [2]).
- overlay support has led to a lot of confusion. It's not really usable
right now and users are not even used to it (see [3]).
This patch aims at solving the aforementioned problems by amending the
PCI topology as follows:
...
pcie@1000120000 {
...
pci@0,0 {
device_type = "pci";
reg = <0x00 0x00 0x00 0x00 0x00>;
...
dev@0,0 {
compatible = "pci1de4,1";
reg = <0x10000 0x00 0x00 0x00 0x00>;
...
pci-ep-bus@1 {
compatible = "simple-bus";
...
/* peripherals child nodes */
};
};
};
};
The reg property is important since it permits the binding the OF
device_node structure to the pci_dev, encoding the BDF in the upper
portion of the address.
This patch also drops the overlay support in favor of the fully
described DT while streamlining it as a result.
Timing could not have been better as I was just going to apply Rob's patch:
https://lore.kernel.org/all/20251211193854.1778221-1-robh@xxxxxxxxxx
Yours is definitively more complete. Rob, Krzysztof, can you review this series and I will fast track it today.
Thanks!
--
Florian