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authorPerry Yuan <Perry.Yuan@amd.com>2022-11-17 15:35:41 +0800
committerRafael J. Wysocki <rafael.j.wysocki@intel.com>2022-11-22 19:57:15 +0100
commit1056d314709d0607a22e589c54b1e47e0da57b9d (patch)
tree8a7bf4c1cbbffae6810200d20057a0aded652f7e /Documentation/admin-guide
parent8a2cbf72a43ade1ed00760f65914e322599fe662 (diff)
downloadlinux-1056d314709d0607a22e589c54b1e47e0da57b9d.tar.gz
Documentation: add amd-pstate kernel command line options
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 <ray.huang@amd.com>
Reviewed-by: Gautham R. Shenoy <gautham.shenoy@amd.com>
Tested-by: Wyes Karny <wyes.karny@amd.com>
Signed-off-by: Perry Yuan <Perry.Yuan@amd.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Diffstat (limited to 'Documentation/admin-guide')
-rw-r--r--Documentation/admin-guide/kernel-parameters.txt11
1 files changed, 11 insertions, 0 deletions
diff --git a/Documentation/admin-guide/kernel-parameters.txt b/Documentation/admin-guide/kernel-parameters.txt
index a465d5242774..42af9ca0127e 100644
--- a/Documentation/admin-guide/kernel-parameters.txt
+++ b/Documentation/admin-guide/kernel-parameters.txt
@@ -6959,3 +6959,14 @@
 				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.)