On Fri, Dec 20, 2024 at 04:15:21PM +0100, Konrad Dybcio wrote: > The Qualcomm platform (or class of platforms) we're looking at with this > specific issue requires PCIe (implying NVMe) shutdown for S2RAM. > > The S2RAM entry mechanism is unfortunately misrepresented as an S2Idle > state by Linux as of today, and I'm trying really hard to convince some > folks to let me describe it correctly, with little success so far.. Well, not advertizing the right mechanism isn't going to cause havoc to any scheme. > That is the real underlying issue and once/if it's solved, this patch > will not be necessary. Well, maybe this thread gave good enough fodder to finally fix it? > > > In theory, ACPI S3 or hibernation may request that, but I've never > > seen it happen in practice. > > > > Suspend-to-idle on x86 may want devices to end up in specific power > > states in order to be able to switch the entire platform into a deep > > energy-saving mode, but that's never been D3cold so far. > > In our case the plug is only pulled in S2RAM, otherwise the best we can > do is just turn off the devices individually to decrease the overall > power draw FYI, going to D3 for S2RAM seems perfectly reasonable from the NVMe POV.
