From: Thomas Gleixner <tglx@kernel.org>
Date: Tue, 3 Feb 2026 21:05:44 +0000 (+0100)
Subject: irqchip/msi-lib: Refuse initialization when irq_write_msi_msg() is missing
X-Git-Url: http://git.ipfire.org/gitweb.cgi?a=commitdiff_plain;h=aa80869b77e16d30ce69523528c63a2e2b050634;p=thirdparty%2Fkernel%2Flinux.git

irqchip/msi-lib: Refuse initialization when irq_write_msi_msg() is missing

MSI parent domains rely on the fact that the top level device domain
provides a irq_write_msi_msg() callback.

Check for that and if missing warn and refuse to initialize the device domain.

Signed-off-by: Thomas Gleixner <tglx@kernel.org>
Link: https://patch.msgid.link/87a4xp35cn.ffs@tglx
---

diff --git a/drivers/irqchip/irq-msi-lib.c b/drivers/irqchip/irq-msi-lib.c
index d5eefc3d72155..45e0ed3134ce1 100644
--- a/drivers/irqchip/irq-msi-lib.c
+++ b/drivers/irqchip/irq-msi-lib.c
@@ -48,6 +48,9 @@ bool msi_lib_init_dev_msi_info(struct device *dev, struct irq_domain *domain,
 		return false;
 	}
 
+	if (WARN_ON_ONCE(!chip->irq_write_msi_msg))
+		return false;
+
 	required_flags = pops->required_flags;
 
 	/* Is the target domain bus token supported? */