Re: [PATCH v2 5/9] PCI: pciehp: Move check for is_thunderbolt into a quirk

Mario Limonciello
2023-11-06T16:50:14Z

On 11/6/2023 06:41, Ilpo Järvinen wrote:
> On Fri, 3 Nov 2023, Mario Limonciello wrote:
>
>> commit 493fb50e958c ("PCI: pciehp: Assume NoCompl+ for Thunderbolt
>> ports") added a check into pciehp code to explicitly set NoCompl+
>> for all Intel Thunderbolt controllers, including those that don't
>> need it.
>>
>> This overloaded the purpose of the `is_thunderbolt` member of
>> `struct pci_device` because that means that any controller that
>> identifies as thunderbolt would set NoCompl+ even if it doesn't
>> suffer this deficiency. As that commit helpfully specifies all the
>> controllers with the problem, move them into a PCI quirk.
>>
>> Signed-off-by: Mario Limonciello <mario.limonciello@amd.com>
>> ---
>> drivers/pci/hotplug/pciehp_hpc.c | 6 +-----
>> drivers/pci/quirks.c | 20 ++++++++++++++++++++
>> include/linux/pci.h | 1 +
>> 3 files changed, 22 insertions(+), 5 deletions(-)
>>
>> diff --git a/drivers/pci/hotplug/pciehp_hpc.c b/drivers/pci/hotplug/pciehp_hpc.c
>> index fd713abdfb9f..23a92d681d1c 100644
>> --- a/drivers/pci/hotplug/pciehp_hpc.c
>> +++ b/drivers/pci/hotplug/pciehp_hpc.c
>> @@ -991,11 +991,7 @@ 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_command_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 eeec1d6f9023..4bbf6e33ca11 100644
>> --- a/drivers/pci/quirks.c
>> +++ b/drivers/pci/quirks.c
>> @@ -3807,6 +3807,26 @@ 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);
>>
>> +/*
>> + * We assume no Thunderbolt controllers support Command Complete events,
>> + * but some controllers falsely claim they do.
>
> IMO, this wording makes little sense with the new code. How about taking
> some text from the original commit's changelog:
>
> /*
> * Certain Thunderbolt 1 controllers falsely claim to support Command
> * Completed events.
> */
>
> The code change looks fine.
>

Ack, will change.