Re: [PATCH] riscv: align pcie bus assign logic with ARM64

[Paul Walmsley]

Hi

On Tue, 22 Sep 2026, sun.wenhan@xxxxxxxxxx wrote:

> RISC-V currently relies on the asm-generic default of
> pcibios_assign_all_busses() returning 1, so the kernel always
> re-assigns all PCI bus numbers and ignores the bus numbers already
> set up by the firmware. This has two downsides:
> 
> 1. As UEFI 2.8 has brought mature firmware support to RISC-V servers,
> the OS can trust and inherit the PCI bus enumeration done by the
> BIOS, skipping a redundant re-enumeration at boot and improving
> the boot time.
> 
> 2. The unconditional re-assignment causes bus numbering conflicts
> during PCI rescan. When a root port that is not the last one in
> the hierarchy is removed and the bus is rescanned, the kernel
> fails with:
> 
> pci_bus 0000:01: busn_res: can not insert [bus 01-ff] under
> [bus 00-ff] (conflicts with (null) [bus 02])
> 
> as reported for the same generic code in commit bd8cbe66c01d
> ("PCI: Make PCI bus renumbering configurable to avoid rescan
> conflicts").
> 
> Define pcibios_assign_all_busses() the same way as ARM64,
> so that RISC-V also preserves the bus numbers assigned by the
> firmware by default instead of always re-assigning them. This keeps
> RISC-V consistent with the other major architectures.
> 
> Signed-off-by: sun wenhan <sun.wenhan@xxxxxxxxxx>

This patch doesn't apply -- see 
https://gist.github.com/linux-riscv-bot/4f238956cd137e576af24c32c44d3437
-- and the commit ID mentioned in the patch description doesn't appear to 
exist in mainline.  Can you please fix these issues and resend?

thanks,


- Paul