Subject: [PATCH 4/6] fsl_mc: Switch over to per-device platform MSI

From: Marc Zyngier <[email-masked]>
Date: Wed, 18 Feb 2026 13:52:01 +0000

Obtain the msi-parent irqdomain instead of the fsl_mc domain,
which magically engages the per-device infrastructure.

Additionally, simplify the overly complicated error handling.

Signed-off-by: Marc Zyngier <[email-masked]>
---
 drivers/bus/fsl-mc/dprc-driver.c | 14 +++++---------
 1 file changed, 5 insertions(+), 9 deletions(-)

diff --git a/drivers/bus/fsl-mc/dprc-driver.c b/drivers/bus/fsl-mc/dprc-driver.c
index c63a7e688db6a..8ee5fb3c2d416 100644
--- a/drivers/bus/fsl-mc/dprc-driver.c
+++ b/drivers/bus/fsl-mc/dprc-driver.c
@@ -620,9 +620,8 @@ int dprc_setup(struct fsl_mc_device *mc_dev)
 {
 	struct device *parent_dev = mc_dev->dev.parent;
 	struct fsl_mc_bus *mc_bus = to_fsl_mc_bus(mc_dev);
-	struct irq_domain *mc_msi_domain;
+	struct irq_domain *mc_msi_domain = NULL;
 	bool mc_io_created = false;
-	bool msi_domain_set = false;
 	bool uapi_created = false;
 	u16 major_ver, minor_ver;
 	size_t region_size;
@@ -663,14 +662,12 @@ int dprc_setup(struct fsl_mc_device *mc_dev)
 		uapi_created = true;
 	}
 
-	mc_msi_domain = fsl_mc_find_msi_domain(&mc_dev->dev);
-	if (!mc_msi_domain) {
+	mc_msi_domain = fsl_mc_get_msi_parent(&mc_dev->dev);
+	if (!mc_msi_domain)
 		dev_warn(&mc_dev->dev,
 			 "WARNING: MC bus without interrupt support\n");
-	} else {
+	else
 		dev_set_msi_domain(&mc_dev->dev, mc_msi_domain);
-		msi_domain_set = true;
-	}
 
 	error = dprc_open(mc_dev->mc_io, 0, mc_dev->obj_desc.id,
 			  &mc_dev->mc_handle);
@@ -710,8 +707,7 @@ int dprc_setup(struct fsl_mc_device *mc_dev)
 	(void)dprc_close(mc_dev->mc_io, 0, mc_dev->mc_handle);
 
 error_cleanup_msi_domain:
-	if (msi_domain_set)
-		dev_set_msi_domain(&mc_dev->dev, NULL);
+	dev_set_msi_domain(&mc_dev->dev, NULL);
 
 	if (mc_io_created) {
 		fsl_destroy_mc_io(mc_dev->mc_io);
-- 
2.47.3