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

["Michal Gorlas" <michal.gorlas@9elements.com>]

On Wed Sep 2, 2026 at 5:36 PM CEST, Manivannan Sadhasivam wrote:
> 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.

Right, 'aspm,no-l1' solves the issue I had. Also forgot to answer
to Krishna's remark in v3 thread. Sorry.

Best,
Michal

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