[PATCH RESEND v2] PCI: imx6: Enable ASPM L1 only iff CLKREQ# is supported

[Manivannan Sadhasivam]

On Wed, Sep 02, 2026 at 04:31:19PM +0200, Manivannan Sadhasivam wrote:
> 
> On Thu, 27 Aug 2026 18:51:00 +0200, Michal Gorlas wrote:
> > Since commit f3ac2ff14834 ("PCI/ASPM: Enable all ClockPM and ASPM
> > states for devicetree platforms"), ASPM states are force enabled
> > on all devicetree platforms. This causes PCI devices on some i.MX SoCs
> > (for e.g. i.MX 8M Plus Kontron SMARC eval carrier) to enter L1 even
> > though CLKREQ# is not supported (and consequently supports-clkreq is
> > not set in pcie controller node of their DT), which causes the device to
> > never wake up from L1.
> > 
> > [...]
> 
> Applied, thanks!
> 
> [1/1] PCI: imx6: Enable ASPM L1 only iff CLKREQ# is supported
>       commit: 94420d27973f567e5c10b631115ea8b9abc0172e
> 

I dropped this patch now as I completely missed that this patch incorrectly
assumed that ASPM L1 is controlled by the 'supports-clkreq' property. This
property is supposed to be used only for ASPM L1ss where REFCLK would be cut
off.

As Krishna explained in v3 [1], you should use 'aspm,no-l1' property in DT and
use it to disable ASPM L1.

- Mani

[1] https://lore.kernel.org/linux-pci/aabc3dbd-3e5b-4272-807f-f0743606e25a@oss.qualcomm.com/

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