Date: Thu, 11 Jun 2026 20:44:17 +0000 From: Aymeric Wibo <obiwac@FreeBSD.org> To: src-committers@FreeBSD.org, dev-commits-src-all@FreeBSD.org, dev-commits-src-main@FreeBSD.org Subject: git: 4733b4dca551 - main - amdsmu(4): Add manpage Message-ID: <6a2b1e21.2225a.451824cd@gitrepo.freebsd.org>
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The branch main has been updated by obiwac: URL: https://cgit.FreeBSD.org/src/commit/?id=4733b4dca5519920a4effa82a62d319c47ef50af commit 4733b4dca5519920a4effa82a62d319c47ef50af Author: Aymeric Wibo <obiwac@FreeBSD.org> AuthorDate: 2026-06-11 20:39:37 +0000 Commit: Aymeric Wibo <obiwac@FreeBSD.org> CommitDate: 2026-06-11 20:43:05 +0000 amdsmu(4): Add manpage Sponsored by: The FreeBSD Foundation Differential Revision: https://reviews.freebsd.org/D57366 --- share/man/man4/Makefile | 2 + share/man/man4/amdsmu.4 | 184 ++++++++++++++++++++++++++++++++++++++++++++++++ 2 files changed, 186 insertions(+) diff --git a/share/man/man4/Makefile b/share/man/man4/Makefile index 4b9740e12081..a66d011f7b62 100644 --- a/share/man/man4/Makefile +++ b/share/man/man4/Makefile @@ -50,6 +50,7 @@ MAN= aac.4 \ ${_amdsbwd.4} \ ${_amdsmb.4} \ ${_amdsmn.4} \ + ${_amdsmu.4} \ ${_amdtemp.4} \ ${_bxe.4} \ ${_aout.4} \ @@ -855,6 +856,7 @@ _aibs.4= aibs.4 _amdsbwd.4= amdsbwd.4 _amdsmb.4= amdsmb.4 _amdsmn.4= amdsmn.4 +_amdsmu.4= amdsmu.4 _amdtemp.4= amdtemp.4 _asmc.4= asmc.4 _atopcase.4= atopcase.4 diff --git a/share/man/man4/amdsmu.4 b/share/man/man4/amdsmu.4 new file mode 100644 index 000000000000..bf36b0a6ec34 --- /dev/null +++ b/share/man/man4/amdsmu.4 @@ -0,0 +1,184 @@ +.\" SPDX-License-Identifier: BSD-2-Clause +.\" +.\" Copyright (c) 2026 The FreeBSD Foundation +.\" +.\" This software was developed by Aymeric Wibo <obiwac@freebsd.org> +.\" under sponsorship from the FreeBSD Foundation. +.\" +.Dd May 30, 2026 +.Dt AMDSMU 4 +.Os +.Sh NAME +.Nm amdsmu +.Nd device driver for the AMD System Management Unit +.Sh SYNOPSIS +To compile this driver into the kernel, +place the following line in your +kernel configuration file: +.Bd -ragged -offset indent +.Cd "device amdsmu" +.Ed +.Pp +Alternatively, to load the driver as a +module at boot time, place the following line in +.Xr rc.conf 5 : +.Bd -literal -offset indent +kld_list="amdsmu" +.Ed +.Sh DESCRIPTION +The +.Nm +driver provides support for the System Management Unit +.Pq SMU +for certain AMD mobile processors. +The SMU is a firmware component responsible for managing system power states, +and in particular for coordinating entry into and exit from the +S0ix suspend-to-idle sleep states. +.Pp +The driver communicates with the SMU over a register-based mailbox interface +to query firmware version information, retrieve power management metrics, +and hint to the SMU when the system is entering or leaving sleep. +The driver registers ACPI suspend and resume event handlers to send the +sleep hint to the SMU and refresh metrics after each sleep cycle. +.Pp +The following AMD processors are supported: +.Pp +.Bl -bullet -compact +.It +Cezanne +.It +Rembrandt +.It +Phoenix +.It +Krackan Point +.El +.Sh SYSCTL VARIABLES +The driver exposes information through the following +.Xr sysctl 8 +variables under the +.Va dev.amdsmu.%d +tree. +.Ss Firmware version +.Bl -tag -width indent +.It Va dev.amdsmu.%d.program +SMU program number. +.It Va dev.amdsmu.%d.version_major +SMU firmware major version number. +.It Va dev.amdsmu.%d.version_minor +SMU firmware minor version number. +.It Va dev.amdsmu.%d.version_revision +SMU firmware revision number. +.El +.Ss Power management metrics +The following variables are located under +.Va dev.amdsmu.%d.metrics +and reflect measurements from the most recent sleep cycle. +Time values are in microseconds. +.Bl -tag -width indent +.It Va dev.amdsmu.%d.metrics.table_version +Version of the SMU metrics table reported by the firmware. +.It Va dev.amdsmu.%d.metrics.hint_count +Number of times the sleep hint has been sent to the SMU. +Incremented each time the system enters suspend-to-idle. +.It Va dev.amdsmu.%d.metrics.s0i3_last_entry_status +Set to 1 if the last S0i3 entry was successful, 0 otherwise. +Useful for diagnosing failed S0i3 transitions. +.It Va dev.amdsmu.%d.metrics.time_last_in_s0i2 +Time spent in S0i2 during the last sleep cycle. +This is not relevant most of the time. +.It Va dev.amdsmu.%d.metrics.time_last_entering_s0i3 +Time spent transitioning into S0i3 during the last sleep cycle. +.It Va dev.amdsmu.%d.metrics.total_time_entering_s0i3 +Total cumulative time spent transitioning into S0i3 across all sleep cycles. +.It Va dev.amdsmu.%d.metrics.time_last_resuming +Time spent resuming from the last sleep cycle. +.It Va dev.amdsmu.%d.metrics.total_time_resuming +Total cumulative time spent resuming from sleep. +.It Va dev.amdsmu.%d.metrics.time_last_in_s0i3 +Time spent in S0i3 during the last sleep cycle. +.It Va dev.amdsmu.%d.metrics.total_time_in_s0i3 +Total cumulative time spent in S0i3 across all sleep cycles. +.It Va dev.amdsmu.%d.metrics.time_last_in_sw_drips +Time the system spent awake +.Pq i.e., not in S0i3 +during the last sleep cycle. +The term "SW DRIPS" is a bit of a misnomer. +.It Va dev.amdsmu.%d.metrics.total_time_in_sw_drips +Total cumulative time the system has spent awake during sleep cycles. +.El +.Ss IP blocks +Each hardware IP block that the SMU tracks is exposed under +.Va dev.amdsmu.%d.ip_blocks.<name> , +where +.Sy <name> +is one of +.Sy DISPLAY , +.Sy CPU , +.Sy GFX , +.Sy VDD , +.Sy ACP , +.Sy VCN , +.Sy ISP , +.Sy NBIO , +.Sy DF , +.Sy LAPIC , +.Sy USB3_0 +through +.Sy USB3_4 , +.Sy USB4_0 , +.Sy USB4_1 , +.Sy MPM , +.Sy JPEG , +.Sy IPU , +.Sy UMSCH , +or +.Sy VPE +(availability depends on the processor model). +Each IP block node contains the following variables: +.Bl -tag -width indent +.It Va dev.amdsmu.%d.ip_blocks.<name>.active +Boolean indicating whether this IP block is active +i.e., whether it could potentially constrain S0i3 entry. +.It Va dev.amdsmu.%d.ip_blocks.<name>.last_time +Time in microseconds that this IP block spent active +.Pq and thus blocking S0i3 entry +during the last sleep cycle. +If this value equals the value of +.Va dev.amdsmu.%d.metrics.time_last_in_sw_drips , +then this IP block was preventing entry into S0i3 during the last cycle. +.El +.Ss Idlemask +.Bl -tag -width indent +.It Va dev.amdsmu.%d.idlemask +Raw idlemask value read from the SMU. +This is an undocumented register intended to assist AMD in debugging +power management issues. +Its interpretation is hardware-specific and not defined by any public +specification. +.El +.Sh SEE ALSO +.Xr acpi 4 , +.Xr amdsmn 4 , +.Xr amdtemp 4 , +.Xr sysctl 8 +.Sh HISTORY +The +.Nm +driver first appeared in +.Fx 15.0 . +.Sh AUTHORS +.An Aymeric Wibo Aq Mt obiwac@FreeBSD.org +.Pp +Development was sponsored by the +.An FreeBSD Foundation . +.Sh BUGS +The +.Va dev.amdsmu.%d.ip_blocks.USB4_0.last_time +value typically contains garbage and should not be relied upon. +.Pp +USB4 blocking S0i3 entry appears to be reported through the +.Va USB3_0 +through +.Va USB3_4 +IP block metrics rather than through the dedicated USB4 blocks.home | help
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