Re: [PATCH] Revert "PCI: qcom: Remove custom ASPM enablement code"

[Manivannan Sadhasivam]

On Mon, Oct 27, 2025 at 05:35:17PM -0500, Bjorn Helgaas wrote:
> On Mon, Oct 27, 2025 at 11:07:51AM +0100, Johan Hovold wrote:
> > On Sun, Oct 26, 2025 at 02:37:54PM -0500, Bjorn Helgaas wrote:
> > > On Sun, Oct 26, 2025 at 08:58:29PM +0530, Manivannan Sadhasivam wrote:
> > 
> > > As far as I know, it's L1SS that has catastrophic effects.  I haven't
> > > seen anything for L0s or L1.
> > 
> > Enabling L0s unconditionally certainly blew up on some Qualcomm
> > machines. See commit d1997c987814 ("PCI: qcom: Disable ASPM L0s for
> > sc8280xp, sa8540p and sa8295p").
> 
> Ah, right, thanks for that reminder.
> 
> IIUC the qcom_pcie_clear_aspm_l0s() quirk that removes L0s from the
> advertised Link Capabilities is still there and prevents df5192d9bb0e
> ("PCI/ASPM: Enable only L0s and L1 for devicetree platforms") from
> being a problem on those platforms, right?

Yes. Since the capability itself is disabled, df5192d9bb0e doesn't affect our
platforms.

- Mani

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