Re: [PATCH] PCI: dw-rockchip: Enumerate endpoints based on dll_link_up irq in the combined sys irq

[Niklas Cassel <cassel@kernel.org>]

On Mon, Dec 30, 2024 at 01:19:08PM -0600, Bjorn Helgaas wrote:
> On Wed, Nov 27, 2024 at 03:50:42PM +0100, Niklas Cassel wrote:
> > Most boards using the pcie-dw-rockchip PCIe controller lack standard
> > hotplug support.
> > 
> > Thus, when an endpoint is attached to the SoC, users have to rescan the bus
> > manually to enumerate the device. This can be avoided by using the
> > 'dll_link_up' interrupt in the combined system interrupt 'sys'.
> > 
> > Once the 'dll_link_up' irq is received, the bus underneath the host bridge
> > is scanned to enumerate PCIe endpoint devices.
> > 
> > This commit implements the same functionality that was implemented in the
> > DWC based pcie-qcom driver in commit 4581403f6792 ("PCI: qcom: Enumerate
> > endpoints based on Link up event in 'global_irq' interrupt").
> > 
> > The Root Complex specific device tree binding for pcie-dw-rockchip already
> > has the 'sys' interrupt marked as required, so there is no need to update
> > the device tree binding. This also means that we can request the 'sys' IRQ
> > unconditionally.
> 
> Thanks for doing this!
> 
> > @@ -436,7 +481,16 @@ static int rockchip_pcie_configure_rc(struct rockchip_pcie *rockchip)
> >  	pp = &rockchip->pci.pp;
> >  	pp->ops = &rockchip_pcie_host_ops;
> >  
> > -	return dw_pcie_host_init(pp);
> > +	ret = dw_pcie_host_init(pp);
> > +	if (ret) {
> > +		dev_err(dev, "failed to initialize host\n");
> > +		return ret;
> > +	}
> > +
> > +	/* unmask DLL up/down indicator */
> > +	rockchip_pcie_writel_apb(rockchip, 0x20000, PCIE_CLIENT_INTR_MASK_MISC);
> 
> I know we already had a bare 0x60000 in rockchip_pcie_configure_ep(),
> but can we add #defines for both of these PCIE_CLIENT_INTR_MASK_MISC
> bits?

Sure, I will send a follow-up patch.


Kind regards,
Niklas