mvebu/pcie: fix DEVCTL change detection and trim RTCTL handling

Compute the relevant PCI_EXP_DEVCTL change mask before clearing the
RC-mode forbidden bits from the local write value. Otherwise a change in
DEVCTL.{CERE,NFERE,FERE} may be missed and the corresponding IRQ mask
update deferred until some later config-space write.

Also restrict the PCI_EXP_RTCTL-triggered IRQ mask update to PMEIE.
mvebu_pcie_handle_irq_change() only uses rootctl.PMEIE, so reacting to
SECEE/SENFEE/SEFEE changes only reruns the helper without affecting the
hardware interrupt mask.

Assisted-by: Claude:claude-opus-4-7

Author: iav

patch/kernel/archive/mvebu-6.18/11-mvebu-pcie-aer-fixes.patch

@@ -0,0 +1,61 @@
+From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001
+From: Igor Velkov <325961+iav@users.noreply.github.com>
+Date: Tue, 22 Apr 2026 00:00:00 +0000
+Subject: mvebu/pcie: fix DEVCTL change detection and trim RTCTL handling
+
+Compute the relevant PCI_EXP_DEVCTL change mask before clearing the
+RC-mode forbidden bits from the local write value. Otherwise a change in
+DEVCTL.{CERE,NFERE,FERE} may be missed and the corresponding IRQ mask
+update deferred until some later config-space write.
+
+Also restrict the PCI_EXP_RTCTL-triggered IRQ mask update to PMEIE.
+mvebu_pcie_handle_irq_change() only uses rootctl.PMEIE, so reacting to
+SECEE/SENFEE/SEFEE changes only reruns the helper without affecting the
+hardware interrupt mask.
+
+---
+ drivers/pci/controller/pci-mvebu.c | 13 ++++++++-----
+ 1 file changed, 8 insertions(+), 5 deletions(-)
+
+diff --git a/drivers/pci/controller/pci-mvebu.c b/drivers/pci/controller/pci-mvebu.c
+--- a/drivers/pci/controller/pci-mvebu.c
++++ b/drivers/pci/controller/pci-mvebu.c
+@@ -865,7 +865,11 @@
+ 	struct mvebu_pcie_port *port = bridge->data;
+
+ 	switch (reg) {
+-	case PCI_EXP_DEVCTL:
++	case PCI_EXP_DEVCTL: {
++		bool aer_changed = (new ^ old) &
++			(PCI_EXP_DEVCTL_FERE | PCI_EXP_DEVCTL_NFERE |
++			 PCI_EXP_DEVCTL_CERE | PCI_EXP_DEVCTL_URRE);
++
+ 		/*
+ 		 * Armada370 data says these bits must always
+ 		 * be zero when in root complex mode.
+@@ -875,10 +879,10 @@
+
+ 		mvebu_writel(port, new, PCIE_CAP_PCIEXP + PCI_EXP_DEVCTL);
+
+-		if ((new ^ old) & (PCI_EXP_DEVCTL_FERE | PCI_EXP_DEVCTL_NFERE |
+-				   PCI_EXP_DEVCTL_CERE | PCI_EXP_DEVCTL_URRE))
++		if (aer_changed)
+ 			mvebu_pcie_handle_irq_change(port);
+ 		break;
++	}
+
+ 	case PCI_EXP_LNKCTL:
+ 		/*
+@@ -941,8 +945,7 @@
+ 		break;
+
+ 	case PCI_EXP_RTCTL:
+-		if ((new ^ old) & (PCI_EXP_RTCTL_SECEE | PCI_EXP_RTCTL_SENFEE |
+-				   PCI_EXP_RTCTL_SEFEE | PCI_EXP_RTCTL_PMEIE))
++		if ((new ^ old) & PCI_EXP_RTCTL_PMEIE)
+ 			mvebu_pcie_handle_irq_change(port);
+ 		break;
+ 	}
+--
+Armbian
+