Re: [PATCH v4] PCI/portdrv: Allow probing even without child services

[sashiko-bot@kernel.org]

> The PCIe port driver fails to probe if it finds no child services,
> presumably under the assumption that the driver is not useful in that case.
> However, the driver *can* still be useful for power management support --
> namely, it still configures the port for runtime PM / D3, which may be
> important for allowing a bridge to enter low power modes.
> 
> Thus, allow probe to succeed even if no IRQs and no child services are
> available. This also mirrors existing behavior for ports that don't support
> any portdrv services (PCIe hotplug, AER, DPC, PME, bwctrl), where we'd also
> probe successfully.
> 
> This change is a bit more important after commit f5cd8a929c82 ("PCI: dwc:
> Remove MSI/MSIX capability for Root Port if iMSI-RX is used as MSI
> controller"), because it's common for some DWC-based systems to:
> 
>   1. have only the "aer" and "pcie_pme" port services available and
> 
>   2. not define legacy INTx interrupts properly in their device tree.
> 
> After commit f5cd8a929c82, such systems may fail pcie_init_service_irqs()
> and so exit with -ENODEV.
> 
> Link: https://lore.kernel.org/all/nyada24tqwlkzdceyoxbzitzygvp4elvj5oajnqdwb33xkcdwk@76vnrx45fsfd/
> Signed-off-by: Brian Norris <briannorris@chromium.org>

Sashiko has reviewed this patch and found no issues. It looks great!

-- 
Sashiko AI review · https://sashiko.dev/#/patchset/20260722160942.v4.1.I5fd5d83f518681b3949d8ab2f16ba8244fd3e774@changeid?part=1