https://bugzilla.kernel.org/show_bug.cgi?id=198779
Bug ID: 198779 Summary: ASRock J3455M (Goldmont) does not reach PC10 Product: ACPI Version: 2.5 Kernel Version: 4.15.0 Hardware: All OS: Linux Tree: Mainline Status: NEW Severity: normal Priority: P1 Component: Power-Processor Assignee: acpi_power-proces...@kernel-bugs.osdl.org Reporter: matts...@gmail.com CC: l...@kernel.org Regression: No Created attachment 274151 --> https://bugzilla.kernel.org/attachment.cgi?id=274151&action=edit turbostat log powertop shows the CPUs in C10, core in C6, and package in C6. No residency in PC10. turbostat agrees. >From the Intel Software Developers' Manual, Vol. 4 [1], I know that there are MSRs for core C1/C3/C6 and package C2/C3/C6/C10. Also confirmed by the commit message of 5c10b048c37c ("perf/x86/intel: Enable C-state residency events for Apollo Lake") In the attached turbostat log, I noticed something odd: cpu1: MSR_PKG_CST_CONFIG_CONTROL: 0x14008072 (... pkg-cstate-limit=2 ...) The BIOS allows you to limit the deepest cstate, with options disabled, C1, C6, C7, C8, C9, C10. I tried each option and did a "rdmsr 0xe2" with each set: BIOS limit powertop reports rdmsr 0xe2 disabled no pkg residency 8000 C1 PC2 14008012 C6 PC6 14008032 C7 PC6 14008042 C8 PC6 14008052 C9 PC6 14008062 C10 PC6 14008072 According to ISD Vol 4 [1] Table 2-12, bits 3:0 of Goldmont's MSR_PKG_CST_CONFIG_CONTROL are: 0000b: No limit 0001b: C1 0010b: C3 0011b: C6 0100b: C7 0101b: C7S 0110b: C8 0111b: C9 1000b: C10 Until C7S, these correspond to bits 7:4 of my readings of 0xe2 (with a missing C3 fitting in as 14008022). The high bits are the lock bit (bit 15) and presumably demote/undemote bits, though those are not documented for Goldmont. Is the BIOS programming the wrong nibble? 0x2 in the low nibble looks like it would be C3 and maybe the undemotion bit would cause the package to use C6? Maybe I'm off on a tangent? [1] https://software.intel.com/sites/default/files/managed/22/0d/335592-sdm-vol-4.pdf -- You are receiving this mail because: You are watching the assignee of the bug. ------------------------------------------------------------------------------ Check out the vibrant tech community on one of the world's most engaging tech sites, Slashdot.org! http://sdm.link/slashdot _______________________________________________ acpi-bugzilla mailing list acpi-bugzilla@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/acpi-bugzilla