On 2/20/24 3:55 PM, Bjorn Helgaas wrote:
> From: Bjorn Helgaas <bhelgaas@xxxxxxxxxx>
>
> When booting with "pci=noaer", we don't request control of AER, but we
> previously *did* request control of DPC, as in the dmesg log attached at
> the bugzilla below:
>
> Command line: ... pci=noaer
> acpi PNP0A08:00: _OSC: OS supports [ExtendedConfig ASPM ClockPM Segments MSI EDR HPX-Type3]
> acpi PNP0A08:00: _OSC: OS now controls [PCIeHotplug SHPCHotplug PME PCIeCapability LTR DPC]
>
> That's illegal per PCI Firmware Spec, r3.3, sec 4.5.1, table 4-5, which
> says:
>
> If the operating system sets this bit [OSC_PCI_EXPRESS_DPC_CONTROL], it
> must also set bit 7 of the Support field (indicating support for Error
> Disconnect Recover notifications) and bits 3 and 4 of the Control field
> (requesting control of PCI Express Advanced Error Reporting and the PCI
> Express Capability Structure).
>
> Request DPC control only if we have also requested AER control.
Can you also add similar check in calculate_support call?
if (pci_aer_available() && IS_ENABLED(CONFIG_PCIE_EDR))
support |= OSC_PCI_EDR_SUPPORT;
>
> Fixes: ac1c8e35a326 ("PCI/DPC: Add Error Disconnect Recover (EDR) support")
> Link: https://bugzilla.kernel.org/show_bug.cgi?id=218491#c12
> Signed-off-by: Bjorn Helgaas <bhelgaas@xxxxxxxxxx>
> Cc: <stable@xxxxxxxxxxxxxxx> # v5.7+
> Cc: Kuppuswamy Sathyanarayanan <sathyanarayanan.kuppuswamy@xxxxxxxxxxxxxxx>
> Cc: Matthew W Carlis <mattc@xxxxxxxxxxxxxxx>
> Cc: Keith Busch <kbusch@xxxxxxxxxx>
> Cc: Lukas Wunner <lukas@xxxxxxxxx>
> Cc: Mika Westerberg <mika.westerberg@xxxxxxxxxxxxxxx>
> Cc: Jesse Brandeburg <jesse.brandeburg@xxxxxxxxx>
> ---
> drivers/acpi/pci_root.c | 20 +++++++++++---------
> 1 file changed, 11 insertions(+), 9 deletions(-)
>
> diff --git a/drivers/acpi/pci_root.c b/drivers/acpi/pci_root.c
> index 58b89b8d950e..1c16965427b3 100644
> --- a/drivers/acpi/pci_root.c
> +++ b/drivers/acpi/pci_root.c
> @@ -518,17 +518,19 @@ static u32 calculate_control(void)
> if (IS_ENABLED(CONFIG_HOTPLUG_PCI_SHPC))
> control |= OSC_PCI_SHPC_NATIVE_HP_CONTROL;
>
> - if (pci_aer_available())
> + if (pci_aer_available()) {
> control |= OSC_PCI_EXPRESS_AER_CONTROL;
>
> - /*
> - * Per the Downstream Port Containment Related Enhancements ECN to
> - * the PCI Firmware Spec, r3.2, sec 4.5.1, table 4-5,
> - * OSC_PCI_EXPRESS_DPC_CONTROL indicates the OS supports both DPC
> - * and EDR.
> - */
> - if (IS_ENABLED(CONFIG_PCIE_DPC) && IS_ENABLED(CONFIG_PCIE_EDR))
> - control |= OSC_PCI_EXPRESS_DPC_CONTROL;
> + /*
> + * Per PCI Firmware Spec, r3.3, sec 4.5.1, table 4-5, the
> + * OS can request DPC control only if it has advertised
> + * OSC_PCI_EDR_SUPPORT and requested both
> + * OSC_PCI_EXPRESS_CAPABILITY_CONTROL and
I think you mean OSC_PCI_EXPRESS_DPC_CONTROL.
> + * OSC_PCI_EXPRESS_AER_CONTROL.
> + */
> + if (IS_ENABLED(CONFIG_PCIE_DPC) && IS_ENABLED(CONFIG_PCIE_EDR))
> + control |= OSC_PCI_EXPRESS_DPC_CONTROL;
Since you are cleaning up this part, why not add a patch to remove
CONFIG_PCIE_EDR?
> + }
>
> return control;
> }
--
Sathyanarayanan Kuppuswamy
Linux Kernel Developer
