From cdbcdfd11e7885bb19b3f75f29401dbde39d5530 Mon Sep 17 00:00:00 2001 From: Perry Yuan Date: Mon, 28 Nov 2022 17:47:55 +0100 Subject: [PATCH] Documentation: add amd-pstate kernel command line options BugLink: https://bugs.launchpad.net/bugs/1998106 Add a new amd pstate driver command line option to enable driver passive working mode via MSR and shared memory interface to request desired performance within abstract scale and the power management firmware (SMU) convert the perf requests into actual hardware pstates. Also the `disable` parameter can disable the pstate driver loading by adding `amd_pstate=disable` to kernel command line. Acked-by: Huang Rui Reviewed-by: Gautham R. Shenoy Tested-by: Wyes Karny Signed-off-by: Perry Yuan Signed-off-by: Rafael J. Wysocki (cherry picked from commit 1056d314709d0607a22e589c54b1e47e0da57b9d) Signed-off-by: Paolo Pisati Acked-by: Tim Gardner Acked-by: Cory Todd Signed-off-by: Luke Nowakowski-Krijger --- Documentation/admin-guide/kernel-parameters.txt | 11 +++++++++++ 1 file changed, 11 insertions(+) diff --git a/Documentation/admin-guide/kernel-parameters.txt b/Documentation/admin-guide/kernel-parameters.txt index bfc1f87aa9ae..b5272568a8f3 100644 --- a/Documentation/admin-guide/kernel-parameters.txt +++ b/Documentation/admin-guide/kernel-parameters.txt @@ -6536,3 +6536,14 @@ memory, and other data can't be written using xmon commands. off xmon is disabled. + + amd_pstate= [X86] + disable + Do not enable amd_pstate as the default + scaling driver for the supported processors + passive + Use amd_pstate as a scaling driver, driver requests a + desired performance on this abstract scale and the power + management firmware translates the requests into actual + hardware states (core frequency, data fabric and memory + clocks etc.) -- 2.39.5