Re: 回覆: [PATCH 7/7] pci: aspeed: Add ASPEED PCIe host controller driver

[Bjorn Helgaas <helgaas@kernel.org>]

On Fri, Jun 20, 2025 at 06:05:20AM +0000, Jacky Chou wrote:
> > > Introduce PCIe Root Complex driver for ASPEED SoCs. Support RC
> > > initialization, reset, clock, IRQ domain, and MSI domain setup.
> > > Implement platform-specific setup and register configuration for
> > > ASPEED. And provide PCI config space read/write and INTx/MSI interrupt
> > > handling.

> > > +static int aspeed_ast2600_rd_conf(struct pci_bus *bus, unsigned int devfn,
> > > +				  int where, int size, u32 *val)
> > > +{
> > > +	struct aspeed_pcie *pcie = bus->sysdata;
> > > +	u32 bdf_offset;
> > > +	int rx_done_fail = 0, slot = PCI_SLOT(devfn);
> > > +	u32 cfg_val, isr, type = 0;
> > > +	u32 link_sts = 0;
> > > +	int ret;
> > > +
> > > +	/* Driver may set unlock RX buffere before triggering next TX config
> > > +*/
> > > +	writel(PCIE_UNLOCK_RX_BUFF | readl(pcie->reg + H2X_DEV_CTRL),
> > > +	       pcie->reg + H2X_DEV_CTRL);
> > > +
> > > +	if (bus->number == 128 && slot != 0 && slot != 8)
> > > +		return PCIBIOS_DEVICE_NOT_FOUND;
> > > +	type = (bus->number > 128);
> > 
> > Weird.  What's all this?  Some kind of device you want to hide?
> > Deserves a hint about what's special.
> 
> The bus range in our AST2600 design is just starting from 128.
> There is no something special.  I will use the child_ops that is in
> struct pci_host_bridge to distinguish the rc bridge and the other
> bus.

Is the 128 root bus number hardwired into the RC?  Maybe it should be
described in DT?