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cdc1719cd8
There is a corner case that if the intel_pstate driver fails to be registered (might be due to invalid MSR access) and acpi_cpufreq takse over, the intel_pstate sysfs interface is still populated which may confuse user space (turbostat for example): grep . /sys/devices/system/cpu/cpu0/cpufreq/scaling_driver acpi-cpufreq grep . /sys/devices/system/cpu/intel_pstate/* /sys/devices/system/cpu/intel_pstate/max_perf_pct:0 /sys/devices/system/cpu/intel_pstate/min_perf_pct:0 grep: /sys/devices/system/cpu/intel_pstate/no_turbo: Resource temporarily unavailable grep: /sys/devices/system/cpu/intel_pstate/num_pstates: Resource temporarily unavailable /sys/devices/system/cpu/intel_pstate/status:off grep: /sys/devices/system/cpu/intel_pstate/turbo_pct: Resource temporarily unavailable The mere presence of the intel_pstate sysfs interface does not mean that intel_pstate is in use (for example, echo "off" to "status"), but it should not be created in the failing case. Fix this issue by deleting the intel_pstate sysfs if the driver registration fails. Reported-by: Wendy Wang <wendy.wang@intel.com> Suggested-by: Zhang Rui <rui.zhang@intel.com> Signed-off-by: Chen Yu <yu.c.chen@intel.com> Acked-by: Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com [ rjw: Refactor code to avoid jumps, change function name, changelog edits ] Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Linux kernel
============
There are several guides for kernel developers and users. These guides can
be rendered in a number of formats, like HTML and PDF. Please read
Documentation/admin-guide/README.rst first.
In order to build the documentation, use ``make htmldocs`` or
``make pdfdocs``. The formatted documentation can also be read online at:
https://www.kernel.org/doc/html/latest/
There are various text files in the Documentation/ subdirectory,
several of them using the Restructured Text markup notation.
Please read the Documentation/process/changes.rst file, as it contains the
requirements for building and running the kernel, and information about
the problems which may result by upgrading your kernel.