On Wed, Oct 16, 2019 at 3:24 AM Daniel Drake <drake@xxxxxxxxxxxx> wrote: > > On Wed, Oct 16, 2019 at 2:43 AM Alex Deucher <alexdeucher@xxxxxxxxx> wrote: > > Is s2idle actually powering down the GPU? > > My understanding is that s2idle (at a high level) just calls all > devices suspend routines and then puts the CPU into its deepest > running state. > So if there is something special to be done to power off the GPU, I > believe that amdgpu is responsible for making arrangements for that to > happen. > In this case the amdgpu code already does: > > pci_disable_device(dev->pdev); > pci_set_power_state(dev->pdev, PCI_D3hot); > > And the PCI layer will call through to any appropriate ACPI methods > related to that low power state. > > > Do you see a difference in power usage? I think you are just working around the fact that the > > GPU never actually gets powered down. > > I ran a series of experiments. > > Base setup: no UI running, ran "setterm -powersave 1; setterm -blank > 1" and waited 1 minute for screen to turn off. > Base power usage in this state is 4.7W as reported by BAT0/power_now > > 1. Run amdgpu_device_suspend(ddev, true, true); before my change > --> Power usage increases to 6.1W > > 2. Run amdgpu_device_suspend(ddev, true, true); with my change applied > --> Power usage increases to 6.0W > > 3. Put amdgpu device in runtime suspend > --> Power usage increases to 6.2W > > 4. Try unmodified suspend path but d3cold instead of d3hot > --> Power usage increases to 6.1W > > So, all of the suspend schemes actually increase the power usage by > roughly the same amount, reset or not, with and without my patch :/ > Any ideas? Do these patches help? https://patchwork.freedesktop.org/patch/341775/ https://patchwork.freedesktop.org/patch/341968/ Alex > > Thanks, > Daniel _______________________________________________ amd-gfx mailing list amd-gfx@xxxxxxxxxxxxxxxxxxxxx https://lists.freedesktop.org/mailman/listinfo/amd-gfx
