PCI: vmd: Disable MSI remapping after suspend

[ Upstream commit d899aa668498c07ff217b666ae9712990306e682 ]

MSI remapping is disabled by VMD driver for Intel's Icelake and
newer systems in order to improve performance by setting
VMCONFIG_MSI_REMAP. By design VMCONFIG_MSI_REMAP register is cleared
by firmware during boot. The same register gets cleared when system
is put in S3 power state. VMD driver needs to set this register again
in order to avoid interrupt issues with devices behind VMD if MSI
remapping was disabled before.

Link: https://lore.kernel.org/r/20221109142652.450998-1-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: Francisco Munoz <francisco.munoz.ruiz@linux.intel.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>

diff --git a/drivers/pci/controller/vmd.c b/drivers/pci/controller/vmd.c
index a5987e5..8dce711 100644 (file)
--- a/drivers/pci/controller/vmd.c
+++ b/drivers/pci/controller/vmd.c
@@ -900,6 +900,11 @@ static int vmd_resume(struct device *dev)
        struct vmd_dev *vmd = pci_get_drvdata(pdev);
        int err, i;
 
+       if (vmd->irq_domain)
+               vmd_set_msi_remapping(vmd, true);
+       else
+               vmd_set_msi_remapping(vmd, false);
+
        for (i = 0; i < vmd->msix_count; i++) {
                err = devm_request_irq(dev, pci_irq_vector(pdev, i),
                                       vmd_irq, IRQF_NO_THREAD,