Update subject to something like:
PCI: pciehp: Quirk broken Command Completed support on Intel Thunderbolt
controllers
On Fri, Feb 11, 2022 at 01:32:40PM -0600, Mario Limonciello wrote:
> The `is_thunderbolt` check is currently used to indicate the lack of
> command completed support for a number of older Thunderbolt devices.
>
> This however is heavy handed and should have been done via a quirk. Move
> the affected devices outlined in commit 493fb50e958c ("PCI: pciehp: Assume
> NoCompl+ for Thunderbolt ports") into pci quirks.
>
> Suggested-by: Lukas Wunner <lu...@wunner.de>
> Signed-off-by: Mario Limonciello <mario.limoncie...@amd.com>
> ---
> drivers/pci/hotplug/pciehp_hpc.c | 6 +-----
> drivers/pci/quirks.c | 17 +++++++++++++++++
> include/linux/pci.h | 2 ++
> 3 files changed, 20 insertions(+), 5 deletions(-)
>
> diff --git a/drivers/pci/hotplug/pciehp_hpc.c
> b/drivers/pci/hotplug/pciehp_hpc.c
> index 1c1ebf3dad43..e4c42b24aba8 100644
> --- a/drivers/pci/hotplug/pciehp_hpc.c
> +++ b/drivers/pci/hotplug/pciehp_hpc.c
> @@ -996,11 +996,7 @@ struct controller *pcie_init(struct pcie_device *dev)
> if (pdev->hotplug_user_indicators)
> slot_cap &= ~(PCI_EXP_SLTCAP_AIP | PCI_EXP_SLTCAP_PIP);
>
> - /*
> - * We assume no Thunderbolt controllers support Command Complete events,
> - * but some controllers falsely claim they do.
> - */
> - if (pdev->is_thunderbolt)
> + if (pdev->no_cmd_complete)
> slot_cap |= PCI_EXP_SLTCAP_NCCS;
>
> ctrl->slot_cap = slot_cap;
> diff --git a/drivers/pci/quirks.c b/drivers/pci/quirks.c
> index d2dd6a6cda60..6d3c88edde00 100644
> --- a/drivers/pci/quirks.c
> +++ b/drivers/pci/quirks.c
> @@ -3675,6 +3675,23 @@ DECLARE_PCI_FIXUP_FINAL(PCI_VENDOR_ID_INTEL,
> PCI_DEVICE_ID_INTEL_CACTUS_RIDGE_4C
> DECLARE_PCI_FIXUP_FINAL(PCI_VENDOR_ID_INTEL, PCI_DEVICE_ID_INTEL_PORT_RIDGE,
> quirk_thunderbolt_hotplug_msi);
Please add a comment above to the effect that PCI_EXP_SLTCAP_NCCS
being clear means the controller generates a Command Completed software
notification when it completes a command, and these controllers don't
generate those notifications even though PCI_EXP_SLTCAP_NCCS is clear
(PCIe r6.0, sec 7.5.3.9).
> +static void quirk_thunderbolt_command_completed(struct pci_dev *pdev)
Rename to quirk_no_command_completed(). This doesn't have anything to
do with Thunderbolt; it's just that the affected devices happen to be
Thunderbolt controllers.
> +{
> + pdev->no_cmd_complete = 1;
> +}
> +DECLARE_PCI_FIXUP_FINAL(PCI_VENDOR_ID_INTEL, PCI_DEVICE_ID_INTEL_LIGHT_RIDGE,
> + quirk_thunderbolt_command_completed);
> +DECLARE_PCI_FIXUP_FINAL(PCI_VENDOR_ID_INTEL, PCI_DEVICE_ID_INTEL_EAGLE_RIDGE,
> + quirk_thunderbolt_command_completed);
> +DECLARE_PCI_FIXUP_FINAL(PCI_VENDOR_ID_INTEL, PCI_DEVICE_ID_INTEL_LIGHT_PEAK,
> + quirk_thunderbolt_command_completed);
> +DECLARE_PCI_FIXUP_FINAL(PCI_VENDOR_ID_INTEL,
> PCI_DEVICE_ID_INTEL_CACTUS_RIDGE_4C,
> + quirk_thunderbolt_command_completed);
> +DECLARE_PCI_FIXUP_FINAL(PCI_VENDOR_ID_INTEL,
> PCI_DEVICE_ID_INTEL_CACTUS_RIDGE_2C,
> + quirk_thunderbolt_command_completed);
> +DECLARE_PCI_FIXUP_FINAL(PCI_VENDOR_ID_INTEL, PCI_DEVICE_ID_INTEL_PORT_RIDGE,
> + quirk_thunderbolt_command_completed);
Can we put these in drivers/pci/hotplug/pciehp_hpc.c? We already
have a few similar quirks there.
> #ifdef CONFIG_ACPI
> /*
> * Apple: Shutdown Cactus Ridge Thunderbolt controller.
> diff --git a/include/linux/pci.h b/include/linux/pci.h
> index 8253a5413d7c..1e5b769e42fc 100644
> --- a/include/linux/pci.h
> +++ b/include/linux/pci.h
> @@ -443,6 +443,8 @@ struct pci_dev {
> unsigned int is_hotplug_bridge:1;
> unsigned int shpc_managed:1; /* SHPC owned by shpchp */
> unsigned int is_thunderbolt:1; /* Thunderbolt controller */
> + unsigned int no_cmd_complete:1; /* Lies about command completed
> events */
> +
> /*
> * Devices marked being untrusted are the ones that can potentially
> * execute DMA attacks and similar. They are typically connected
> --
> 2.34.1
>
