From: Kai-Heng Feng Date: Fri, 3 Dec 2021 03:15:41 +0000 (+0800) Subject: PCI: vmd: Honor ACPI _OSC on PCIe features X-Git-Url: http://git.maquefel.me/?a=commitdiff_plain;h=04b12ef163d10e348db664900ae7f611b83c7a0e;p=linux.git PCI: vmd: Honor ACPI _OSC on PCIe features When Samsung PCIe Gen4 NVMe is connected to Intel ADL VMD, the combination causes AER message flood and drags the system performance down. The issue doesn't happen when VMD mode is disabled in BIOS, since AER isn't enabled by acpi_pci_root_create() . When VMD mode is enabled, AER is enabled regardless of _OSC: [ 0.410076] acpi PNP0A08:00: _OSC: platform does not support [AER] ... [ 1.486704] pcieport 10000:e0:06.0: AER: enabled with IRQ 146 Since VMD is an aperture to regular PCIe root ports, honor ACPI _OSC to disable PCIe features accordingly to resolve the issue. Suggested-by: Rafael J. Wysocki Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=215027 Link: https://lore.kernel.org/r/20211203031541.1428904-1-kai.heng.feng@canonical.com Signed-off-by: Kai-Heng Feng Signed-off-by: Lorenzo Pieralisi Reviewed-by: Rafael J. Wysocki --- diff --git a/drivers/pci/controller/vmd.c b/drivers/pci/controller/vmd.c index 02ffd40108e2f..5c9211dee93ee 100644 --- a/drivers/pci/controller/vmd.c +++ b/drivers/pci/controller/vmd.c @@ -695,6 +695,21 @@ static int vmd_alloc_irqs(struct vmd_dev *vmd) return 0; } +/* + * Since VMD is an aperture to regular PCIe root ports, only allow it to + * control features that the OS is allowed to control on the physical PCI bus. + */ +static void vmd_copy_host_bridge_flags(struct pci_host_bridge *root_bridge, + struct pci_host_bridge *vmd_bridge) +{ + vmd_bridge->native_pcie_hotplug = root_bridge->native_pcie_hotplug; + vmd_bridge->native_shpc_hotplug = root_bridge->native_shpc_hotplug; + vmd_bridge->native_aer = root_bridge->native_aer; + vmd_bridge->native_pme = root_bridge->native_pme; + vmd_bridge->native_ltr = root_bridge->native_ltr; + vmd_bridge->native_dpc = root_bridge->native_dpc; +} + static int vmd_enable_domain(struct vmd_dev *vmd, unsigned long features) { struct pci_sysdata *sd = &vmd->sysdata; @@ -832,6 +847,9 @@ static int vmd_enable_domain(struct vmd_dev *vmd, unsigned long features) return -ENODEV; } + vmd_copy_host_bridge_flags(pci_find_host_bridge(vmd->dev->bus), + to_pci_host_bridge(vmd->bus->bridge)); + vmd_attach_resources(vmd); if (vmd->irq_domain) dev_set_msi_domain(&vmd->bus->dev, vmd->irq_domain);