On Wed, Mar 06, 2024 at 10:12:31AM +0100, Johan Hovold wrote: > On Wed, Mar 06, 2024 at 10:48:30AM +0200, Dmitry Baryshkov wrote: > > On Wed, 6 Mar 2024 at 10:39, Manivannan Sadhasivam > > <manivannan.sadhasivam@xxxxxxxxxx> wrote: > > > On Wed, Mar 06, 2024 at 08:20:16AM +0100, Johan Hovold wrote: > > > > On Wed, Mar 06, 2024 at 12:03:02PM +0530, Manivannan Sadhasivam wrote: > > > > > > Just received confirmation from Qcom that L0s is not supported for any of the > > > > > PCIe instances in sc8280xp (and its derivatives). Please move the property to > > > > > SoC dtsi. > > > > > Ok, thanks for confirming. But then the devicetree property is not the > > > > right way to handle this, and we should disable L0s based on the > > > > compatible string instead. > > > > Hmm. I checked further and got the info that there is no change in the IP, but > > > the PHY sequence is not tuned correctly for L0s (as I suspected earlier). So > > > there will be AERs when L0s is enabled on any controller instance. And there > > > will be no updated PHY sequence in the future also for this chipset. > > > > Why? If it is a bug in the PHY driver, it should be fixed there > > instead of adding workarounds. > > ASPM L0s is currently broken on these platforms and, as far as I > understand, both under Windows and Linux. Since Qualcomm hasn't been > able to come up with the necessary PHY init sequences for these > platforms yet, I doubt they will suddenly appear in the near future. > > So we need to disable L0s for now. If an updated PHY init sequence later > appears, we can always enable it again. > It could be the same case for all 'non-mobile' chipsets (automotive, compute, modem). So instead of using the compatible, please add a flag and set that for all non-mobile SoCs. Like the ones starting with SAxxx, SCxxx, SDxxx. - Mani -- மணிவண்ணன் சதாசிவம்
