Not sure whether anybody cares about the keystone driver any more. It
seems basically unmaintained after 57e1d8206e48 ("MAINTAINERS: move
Murali Karicheri to credits") [1].
Anyway, ks_pcie_v3_65_add_bus() [2] looks unusual to me. It's an
.add_bus() method that is called whenever we create a new PCI bus:
ks_pcie_v3_65_add_bus(...)
{
ks_pcie_set_dbi_mode
dw_pcie_writel_dbi(pci, PCI_BASE_ADDRESS_0, 1)
dw_pcie_writel_dbi(pci, PCI_BASE_ADDRESS_0, SZ_4K - 1)
ks_pcie_clear_dbi_mode(ks_pcie)
dw_pcie_writel_dbi(pci, PCI_BASE_ADDRESS_0, ks_pcie->app.start)
}
This seems like something that should be done when the Root Port is
enumerated, not when we set up its secondary bus. Maybe somewhere in
ks_pcie_host_init() or ks_pcie_config_msi_irq()?
I don't think we should use .add_bus() unless it's actually something
related to adding a bus.
[1] https://git.kernel.org/linus/57e1d8206e48
[2] https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/tree/drivers/pci/controller/dwc/pci-keystone.c?id=v5.18#n452
