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: Marc Zyngier <maz@xxxxxxxxxx>
---
drivers/pci/controller/pci-xgene.c | 23 +++++++++++++++++++++++
1 file changed, 23 insertions(+)
diff --git a/drivers/pci/controller/pci-xgene.c b/drivers/pci/controller/pci-xgene.c
index 1e2ebbfa36d19..f26cb58f814ec 100644
--- a/drivers/pci/controller/pci-xgene.c
+++ b/drivers/pci/controller/pci-xgene.c
@@ -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;
--
2.39.2
