From b61cf04c49c3dfa70a0d6725d3eb40bf9b35cf71 Mon Sep 17 00:00:00 2001
From: Nirmal Patel <nirmal.patel@linux.intel.com>
Date: Fri, 24 Feb 2023 13:28:11 -0700
Subject: [PATCH] PCI: vmd: Reset VMD config register between soft reboots
Git-commit: b61cf04c49c3dfa70a0d6725d3eb40bf9b35cf71
Patch-mainline: v6.5-rc1
References: git-fixes

VMD driver can disable or enable MSI remapping by changing
VMCONFIG_MSI_REMAP register. This register needs to be set to the
default value during soft reboots. Drives failed to enumerate
when Windows boots after performing a soft reboot from Linux.
Windows doesn't support MSI remapping disable feature and stale
register value hinders Windows VMD driver initialization process.
Adding vmd_shutdown function to make sure to set the VMCONFIG
register to the default value.

Link: https://lore.kernel.org/r/20230224202811.644370-1-nirmal.patel@linux.intel.com
Fixes: ee81ee84f873 ("PCI: vmd: Disable MSI-X remapping when possible")
Signed-off-by: Nirmal Patel <nirmal.patel@linux.intel.com>
Signed-off-by: Lorenzo Pieralisi <lpieralisi@kernel.org>
Reviewed-by: Jon Derrick <jonathan.derrick@linux.dev>
Acked-by: Takashi Iwai <tiwai@suse.de>

---
 drivers/pci/controller/vmd.c |    8 ++++++++
 1 file changed, 8 insertions(+)

--- a/drivers/pci/controller/vmd.c
+++ b/drivers/pci/controller/vmd.c
@@ -829,6 +829,13 @@ static void vmd_remove(struct pci_dev *d
 	vmd_remove_irq_domain(vmd);
 }
 
+static void vmd_shutdown(struct pci_dev *dev)
+{
+        struct vmd_dev *vmd = pci_get_drvdata(dev);
+
+        vmd_remove_irq_domain(vmd);
+}
+
 #ifdef CONFIG_PM_SLEEP
 static int vmd_suspend(struct device *dev)
 {
@@ -894,6 +901,7 @@ static struct pci_driver vmd_drv = {
 	.id_table	= vmd_ids,
 	.probe		= vmd_probe,
 	.remove		= vmd_remove,
+	.shutdown	= vmd_shutdown,
 	.driver		= {
 		.pm	= &vmd_dev_pm_ops,
 	},