On Wed, Dec 1, 2021 at 7:25 AM Kai-Heng Feng <kai.heng.feng@xxxxxxxxxxxxx> wrote: > > 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. > > Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=215027 > Signed-off-by: Kai-Heng Feng <kai.heng.feng@xxxxxxxxxxxxx> > --- > drivers/pci/controller/vmd.c | 18 +++++++++++++++++- > 1 file changed, 17 insertions(+), 1 deletion(-) > > diff --git a/drivers/pci/controller/vmd.c b/drivers/pci/controller/vmd.c > index a45e8e59d3d48..8298862417e84 100644 > --- a/drivers/pci/controller/vmd.c > +++ b/drivers/pci/controller/vmd.c > @@ -670,7 +670,8 @@ static int vmd_enable_domain(struct vmd_dev *vmd, unsigned long features) > LIST_HEAD(resources); > resource_size_t offset[2] = {0}; > resource_size_t membar2_offset = 0x2000; > - struct pci_bus *child; > + struct pci_bus *child, *bus; > + struct pci_host_bridge *root_bridge, *vmd_bridge; > int ret; > > /* > @@ -798,6 +799,21 @@ static int vmd_enable_domain(struct vmd_dev *vmd, unsigned long features) > return -ENODEV; > } > > + vmd_bridge = to_pci_host_bridge(vmd->bus->bridge); > + > + bus = vmd->dev->bus; > + while (bus->parent) > + bus = bus->parent; What about using pci_fimd_host_bridge() here? LGTM otherwise. > + > + root_bridge = to_pci_host_bridge(bus->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; > + > vmd_attach_resources(vmd); > if (vmd->irq_domain) > dev_set_msi_domain(&vmd->bus->dev, vmd->irq_domain); > -- > 2.32.0 >
