Hello. On středa 20. září 2023 18:56:09 CEST Mario Limonciello wrote: > > When applied on top of v6.5.3 this breaks turbo on my 5950X after suspend/resume cycle. Please see the scenario description below. > > > > If I boot v6.5.3 + this patchset, then `turbostat` reports ~4.9 GHz on core 0 where `taskset -c 0 dd if=/dev/zero of=/dev/null` is being run. > > > > After I suspend the machine and then resume it, and run `dd` again, `turbostat` reports the core to be capped to a stock frequency of ~3.4 GHz. Rebooting the machine fixes this, and the CPU can boost again. > > > > If this patchset is reverted, then the CPU can turbo after suspend/resume cycle just fine. > > > > I'm using `amd_pstate=guided`. > > > > Is this behaviour expected? > > To help confirm where the issue is, can I ask you to do three > experiments with the patch series applied: > > 1) 'amd_pstate=active' on your kernel command line. The issue is reproducible. If I toggle the governor in cpupower to `powersave` and back to `performance`, boost is restored. > 2) 'amd_pstate=active amd_prefcore=disable' on your kernel command line. The issue is not reproducible. > 3) 'amd_pstate=guided amd_prefcore=disable' on your kernel command line. The issue is not reproducible. I should also mention that in my initial configuration I use `amd_pstate=guided` and `schedutil`. If I switch to `performance` after suspend-resume cycle, the boost is restored. However, if I switch back to `schedutil`, the freq is capped. Does this info help? > Looking through the code, I anticipate from your report that it > reproduces on "1" but not "2" and "3". > > Meng, > > Can you try to repro? > > I think that it's probably a call to amd_pstate_init_prefcore() missing > from amd_pstate_cpu_resume() and also amd_pstate_epp_resume(). -- Oleksandr Natalenko (post-factum)
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