Commit 0d402bd4 authored by Marc Zyngier's avatar Marc Zyngier Committed by Bjorn Helgaas
Browse files

PCI: xgene: Defer probing if the MSI widget driver hasn't probed yet 



As a preparatory work to make the XGene MSI driver probe less of
a sorry hack, make the PCI driver check for the availability of
the MSI parent domain, and defer the probing otherwise.

Signed-off-by: default avatarMarc Zyngier <maz@kernel.org>
Signed-off-by: default avatarLorenzo Pieralisi <lpieralisi@kernel.org>
Signed-off-by: default avatarBjorn Helgaas <bhelgaas@google.com>
Link: https://lore.kernel.org/r/20250708173404.1278635-3-maz@kernel.org
parent 2c9e7f85

drivers/pci/controller/pci-xgene.c

+23 −0
Original line number Diff line number Diff line
@@ -12,6 +12,7 @@ 
#include <linux/jiffies.h>

#include <linux/memblock.h>

#include <linux/init.h>

#include <linux/irqdomain.h>

#include <linux/of.h>

#include <linux/of_address.h>

#include <linux/of_pci.h>
@@ -594,6 +595,24 @@ static struct pci_ops xgene_pcie_ops = { 
	.write = pci_generic_config_write32,

};



static bool xgene_check_pcie_msi_ready(void)

{

	struct device_node *np;

	struct irq_domain *d;



	if (!IS_ENABLED(CONFIG_PCI_XGENE_MSI))

		return true;



	np = of_find_compatible_node(NULL, NULL, "apm,xgene1-msi");

	if (!np)

		return true;



	d = irq_find_matching_host(np, DOMAIN_BUS_PCI_MSI);

	of_node_put(np);



	return d && irq_domain_is_msi_parent(d);

}



static int xgene_pcie_probe(struct platform_device *pdev)

{

	struct device *dev = &pdev->dev;
@@ -602,6 +621,10 @@ static int xgene_pcie_probe(struct platform_device *pdev) 
	struct pci_host_bridge *bridge;

	int ret;



	if (!xgene_check_pcie_msi_ready())

		return dev_err_probe(&pdev->dev, -EPROBE_DEFER,

				     "MSI driver not ready\n");



	bridge = devm_pci_alloc_host_bridge(dev, sizeof(*port));

	if (!bridge)

		return -ENOMEM;