On Mon, Jul 19, 2021 at 07:23:40PM +0200, Pali Rohár wrote: > > On Sat, Jul 17, 2021 at 12:33:34PM -0500, Bjorn Helgaas wrote: > > > - "The R-Car PCIe controller is capable of handling L0s/L1 link > > > states." AFAICT every PCIe device is required to handle L0 and L1 > > > without software assistance. So saying R-Car is "capable" puts a > > > better face on this than seems warranted. > > > > > > L0s doesn't seem relevant at all; at least it doesn't seem to play > > > a role in the patch. There's no such thing as "returning to L0s" > > > as mentioned in the comment below; L0s is only reachable from L0. > > > Returns from L1 only go to L0 (PCIe r5.0, fig 5-1). > > IIRC from L1 you can only go to Recovery. And from L0s you go to L0 or > Recovery. But I do not know what is or was changed in PCIe r5.0. Yes. Per PCIe r5.0, fig 4-26, the LTSSM state diagram, that's still the same. The overview in Fig 5-1 doesn't include Recovery, Detect, and othef LTSSM states.