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

[Mario Limonciello]

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@xxxxxxx>
> > ---
> >   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.