[PATCH RFC 01/11] ACPI: irq: Return -EPROBE_DEFER on missing IRQ domain

[Lorenzo Pieralisi]

acpi_register_gsi() might fail if the IRQ domain a GSI belongs to has
not been registered yet by the respective interrupt controller driver.

Return -EPROBE_DEFER in this case so that the mapping can be retried
later by deferring the probe for the driver that requested the IRQ
mapping.

Signed-off-by: Lorenzo Pieralisi <lpieralisi@xxxxxxxxxx>
Cc: "Rafael J. Wysocki" <rafael@xxxxxxxxxx>
Cc: Marc Zyngier <maz@xxxxxxxxxx>
---
 drivers/acpi/irq.c | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/drivers/acpi/irq.c b/drivers/acpi/irq.c
index e4293458bf61..d1f1938c83bf 100644
--- a/drivers/acpi/irq.c
+++ b/drivers/acpi/irq.c
@@ -52,11 +52,13 @@ EXPORT_SYMBOL_GPL(acpi_gsi_to_irq);
  * @polarity: polarity of the GSI to be mapped
  *
  * Returns: a valid linux IRQ number on success
+ *          -EPROBE_DEFER when the domain was not yet registered
  *          -EINVAL on failure
  */
 int acpi_register_gsi(struct device *dev, u32 gsi, int trigger,
 		      int polarity)
 {
+	struct irq_domain *domain;
 	struct irq_fwspec fwspec;
 	unsigned int irq;
 
@@ -66,6 +68,10 @@ int acpi_register_gsi(struct device *dev, u32 gsi, int trigger,
 		return -EINVAL;
 	}
 
+	domain = irq_find_matching_fwnode(fwspec.fwnode, DOMAIN_BUS_ANY);
+	if (!domain)
+		return -EPROBE_DEFER;
+
 	fwspec.param[0] = gsi;
 	fwspec.param[1] = acpi_dev_get_irq_type(trigger, polarity);
 	fwspec.param_count = 2;

-- 
2.54.0