Re: [PPC] Boot problems after the pci-v6.18-changes

[Bjorn Helgaas <helgaas@kernel.org>]

On Thu, Nov 06, 2025 at 08:48:16AM +0000, Hongxing Zhu wrote:
> ...

> I tested these patches on i.MX95 EVK board with NVME storage device.
> Because that i.MX95 PCIe RC failed enter into L2 when one NVME
> device is connected to the port if ASPM L1 is enabled in default.
> 
> These patches work as expected, the l0s and l1 can be disabled after
> adding the following quirk.
> 
> "DECLARE_PCI_FIXUP_HEADER(PCI_VENDOR_ID_PHILIPS, PCI_ANY_ID,
> quirk_disable_aspm_l0s_l1_cap);"

Thanks for trying this out.

So if I understand correctly, the i.MX95 Root Port has
PCI_VENDOR_ID_PHILIPS, and if ASPM L1 is enabled on its link, the link
doesn't go to L2 when suspending?  But it *does* go to L2 on suspend
if L1 is disabled?

I wonder if the issue is with the RC or with the NVMe device.  The
comments in dw_pcie_suspend_noirq() and qcom_pcie_suspend_noirq() make
me wonder if there's something weird about NVMe and L2.

I assume you don't want to disable L0s and L1 for *all* devices with
PCI_VENDOR_ID_PHILIPS though.  Aren't there endpoints with that ID
that can use L0s and L1?

And I suppose the best thing would be if we could enable L0s and L1,
but turn them off before suspending?  That would require something
different, like something in imx_pcie_suspend_noirq() or a
DECLARE_PCI_FIXUP_SUSPEND() quirk.