On Mon, May 01, 2017 at 10:41:20PM -0400, Sinan Kaya wrote: > On 5/1/2017 9:54 PM, Lukas Wunner wrote: > > (b) ASPM L1 enabled on boot, but disabled after powering off and back on > > => I believe Sinan is working on this (+cc). > > The decision was made not to touch ASPM registers following hotplug insertion > unless pcie_aspm.policy=powersave is specified. > > The discussion is here: https://lkml.org/lkml/2017/4/17/255 > > This was done to maintain existing behavior and not break things. Thanks for the reference, I hadn't followed the discussion in April very closely, but I think the outcome of the discussion is unfortunate. As can be seen in Ashok's tests, merely turning slot power off and back on is sufficient to end up with a setting that draws more power. That may be equally surprising for users as the issues would be that we seek to avoid with a "safety-first" ASPM policy. In any case it seems undesirable. I hope this is not the end if it and would like to encourage you to keep working on this. Perhaps it is too simple to just define a default policy, and what is really needed is a policy that adjusts itself dynamically to specific devices or workloads, or that can be influenced by device drivers. Thanks for your efforts, Lukas
