Frequency scaling driver intel_pstate not loading on some Intel Xeon Scalable processors
This document (000020273) is provided subject to the disclaimer at the end of this document.
Environment
SUSE Linux Enterprise Server 15 SP3
SUSE Linux Enterprise Server 15 SP2
SUSE Linux Enterprise Server 12 SP5
SUSE Linux Enterprise Server 15 SP2
SUSE Linux Enterprise Server 12 SP5
Situation
On x86_64 systems running Intel Xeon processors identified by Family = 6 and
Model = 106, the intel_pstate frequency scaling driver may not load, showing the message
intel_pstate: CPU model not supported
in the kernel log at boot.
The affected processors were formerly known under the codename "Icelake". This situation may present on successive processor models as well.
Model = 106, the intel_pstate frequency scaling driver may not load, showing the message
intel_pstate: CPU model not supported
in the kernel log at boot.
The affected processors were formerly known under the codename "Icelake". This situation may present on successive processor models as well.
Resolution
The issue is resolved in the following system kernel updates:
SLES15 SP3
kernel-default-5.3.18-59.5
kernel-rt (See Workaround below)
kernel-azure-5.3.18-38.3
SLES15 SP2
kernel-default-5.3.18-24.67
kernel-rt-5.3.18-39.1
kernel-azure-5.3.18-18.50
SLES12 SP5
kernel-default-4.12.14-122.74
kernel-rt-4.12.14-10.46
kernel-azure-4.12.14-16.59
Workaround:
To load the intel_pstate frequency scaling driver, it is necessary to leave the HWP/SpeedShift feature enabled in the BIOS configuration.
In case such feature is undesired, it can be disabled using the kernel command line option during boot :
intel_pstate=no_hwp
SLES15 SP3
kernel-default-5.3.18-59.5
kernel-rt (See Workaround below)
kernel-azure-5.3.18-38.3
SLES15 SP2
kernel-default-5.3.18-24.67
kernel-rt-5.3.18-39.1
kernel-azure-5.3.18-18.50
SLES12 SP5
kernel-default-4.12.14-122.74
kernel-rt-4.12.14-10.46
kernel-azure-4.12.14-16.59
Workaround:
To load the intel_pstate frequency scaling driver, it is necessary to leave the HWP/SpeedShift feature enabled in the BIOS configuration.
In case such feature is undesired, it can be disabled using the kernel command line option during boot :
intel_pstate=no_hwp
Cause
The situation exists when the Hardware-Managed P-States (HWP) feature is disabled using the BIOS configuration utility. The feature is also known as Intel Speed Shift technology, and the BIOS may refer to it as such.
Status
Reported to Engineering
Additional Information
SUSE is planning to release kernel updates containing a code change, that enable load of the intel_pstate driver when the HWP/SpeedShift feature is disabled by the BIOS.
Until such a (future) kernel has installed on a system, it will be necessary to follow the workaround procedure outlined above.
This document will be updated with version information about the maintenance kernels as they get released.
Until such a (future) kernel has installed on a system, it will be necessary to follow the workaround procedure outlined above.
This document will be updated with version information about the maintenance kernels as they get released.
Disclaimer
This Support Knowledgebase provides a valuable tool for SUSE customers and parties interested in our products and solutions to acquire information, ideas and learn from one another. Materials are provided for informational, personal or non-commercial use within your organization and are presented "AS IS" WITHOUT WARRANTY OF ANY KIND.
- Document ID:000020273
- Creation Date: 04-Jun-2021
- Modified Date:16-Jun-2021
-
- SUSE Linux Enterprise Server
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