On Wed, Nov 25, 2020 at 02:21:49PM -0800, Kuppuswamy, Sathyanarayanan wrote:
> Hi Bjorn,
>
> Thanks for the review.
>
> On 11/25/20 12:12 PM, Bjorn Helgaas wrote:
> > On Mon, Oct 26, 2020 at 07:57:05PM -0700, Kuppuswamy Sathyanarayanan wrote:
> > > pcie_ports_native is set only if user requests native handling
> > > of PCIe capabilities via pcie_port_setup command line option.
> > > User input takes precedence over _OSC based control negotiation
> > > result. So consider the _OSC negotiated result only if
> > > pcie_ports_native is unset.
> > >
> > > Also, since struct pci_host_bridge ->native_* members caches the
> > > ownership status of various PCIe capabilities, use them instead
> > > of distributed checks for pcie_ports_native.
> > >
> > > Signed-off-by: Kuppuswamy Sathyanarayanan <sathyanarayanan.kuppuswamy@xxxxxxxxxxxxxxx>
> > > ---
> > > drivers/acpi/pci_root.c | 35 ++++++++++++++++++++++---------
> > > drivers/pci/hotplug/pciehp_core.c | 2 +-
> > > drivers/pci/pci-acpi.c | 3 ---
> > > drivers/pci/pcie/aer.c | 2 +-
> > > drivers/pci/pcie/portdrv_core.c | 9 +++-----
> > > include/linux/acpi.h | 2 ++
> > > 6 files changed, 32 insertions(+), 21 deletions(-)
> > >
> > > diff --git a/drivers/acpi/pci_root.c b/drivers/acpi/pci_root.c
> > > index c12b5fb3e8fb..a9e6b782622d 100644
> > > --- a/drivers/acpi/pci_root.c
> > > +++ b/drivers/acpi/pci_root.c
> > > @@ -41,6 +41,12 @@ static int acpi_pci_root_scan_dependent(struct acpi_device *adev)
> > > | OSC_PCI_CLOCK_PM_SUPPORT \
> > > | OSC_PCI_MSI_SUPPORT)
>
> > > +
> > > + if (pcie_ports_native) {
> > > + decode_osc_control(root, "OS forcibly taking over",
> > > + OSC_PCI_EXPRESS_CONTROL_MASKS);
> >
> > The only place OSC_PCI_EXPRESS_CONTROL_MASKS is used is right here, so
> > it's kind of pointless.
> >
> > I think I'd rather have this:
> >
> > dev_info(&root->device->dev, "Ignoring PCIe-related _OSC results because \"pcie_ports=native\" specified\n");
> I was trying to keep the same print format. In pci_root.c,
> decode_os_control() is repeatedly used to print info related to
> PCIe capability ownership.
>
> But either way is fine with me. I can use the format you mentioned.
> >
> >
> > followed by something like this after we're done fiddling with all the
> > host_bridge->native* bits:
> >
>
> > #define FLAG(x) ((x) ? '+' : '-')
> >
> > dev_info(&root->device->dev, "OS native features: SHPCHotplug%c PCIeCapability%c PCIeHotplug%c PME%c AER%c DPC%c LTR%c\n",
> > FLAG(host_bridge->native_shpc_hotplug),
> > ?,
> > FLAG(host_bridge->native_pcie_hotplug),
> > ...);
> >
> > But I don't know how to handle OSC_PCI_EXPRESS_CAPABILITY_CONTROL
> > since we don't track it the same way. Maybe we'd have to omit it from
> > this message for now?
> I will add it in next version. But for now, its not worry about
> OSC_PCI_EXPRESS_CAPABILITY_CONTROL.
I've been fiddling with this, so let me post a v12 tonight and you can
see what you think.
> > > /*
> > > * Evaluate the "PCI Boot Configuration" _DSM Function. If it
>
> > > --
> > > 2.17.1
> > >
>
> --
> Sathyanarayanan Kuppuswamy
> Linux Kernel Developer
