Find a file
Chen Yu cdc1719cd8 cpufreq: intel_pstate: Delete intel_pstate sysfs if failed to register the driver
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>
2020-10-16 16:33:12 +02:00
arch Power management updates for 5.10-rc1 2020-10-14 10:45:41 -07:00
block drivers-5.10-2020-10-12 2020-10-13 13:04:41 -07:00
certs .gitignore: add SPDX License Identifier 2020-03-25 11:50:48 +01:00
crypto drivers-5.10-2020-10-12 2020-10-13 13:04:41 -07:00
Documentation Power management updates for 5.10-rc1 2020-10-14 10:45:41 -07:00
drivers cpufreq: intel_pstate: Delete intel_pstate sysfs if failed to register the driver 2020-10-16 16:33:12 +02:00
fs mm, oom_adj: don't loop through tasks in __set_oom_adj when not necessary 2020-10-13 18:38:35 -07:00
include Power management updates for 5.10-rc1 2020-10-14 10:45:41 -07:00
init printk changes for 5.10 2020-10-13 15:58:10 -07:00
ipc ipc: adjust proc_ipc_sem_dointvec definition to match prototype 2020-09-05 12:14:29 -07:00
kernel Power management updates for 5.10-rc1 2020-10-14 10:45:41 -07:00
lib mm/page_alloc.c: fix freeing non-compound pages 2020-10-13 18:38:33 -07:00
LICENSES LICENSES: Rename other to deprecated 2019-05-03 06:34:32 -06:00
mm mm/migrate: remove obsolete comment about device public 2020-10-13 18:38:36 -07:00
net io_uring-5.10-2020-10-12 2020-10-13 12:36:21 -07:00
samples mm,kmemleak-test.c: move kmemleak-test.c to samples dir 2020-10-13 18:38:27 -07:00
scripts Merge branch 'akpm' (patches from Andrew) 2020-10-14 09:57:24 -07:00
security selinux/stable-5.10 PR 20201012 2020-10-13 16:29:55 -07:00
sound sound fixes for 5.9-rc7 2020-09-24 09:00:05 -07:00
tools platform-drivers-x86 for v5.10-1 2020-10-14 10:43:24 -07:00
usr Merge branch 'work.fdpic' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2020-08-07 13:29:39 -07:00
virt KVM: fix memory leak in kvm_io_bus_unregister_dev() 2020-09-11 13:15:11 -04:00
.clang-format memblock: use separate iterators for memory and reserved regions 2020-10-13 18:38:35 -07:00
.cocciconfig
.get_maintainer.ignore Opt out of scripts/get_maintainer.pl 2019-05-16 10:53:40 -07:00
.gitattributes .gitattributes: use 'dts' diff driver for dts files 2019-12-04 19:44:11 -08:00
.gitignore .gitignore: docs: ignore sphinx_*/ directories 2020-09-10 10:44:31 -06:00
.mailmap As hoped, things calmed down for docs this cycle; fewer changes and almost 2020-10-12 16:21:29 -07:00
COPYING COPYING: state that all contributions really are covered by this file 2020-02-10 13:32:20 -08:00
CREDITS CREDITS: Replace HTTP links with HTTPS ones 2020-07-23 14:53:58 -06:00
Kbuild kbuild: rename hostprogs-y/always to hostprogs/always-y 2020-02-04 01:53:07 +09:00
Kconfig kbuild: ensure full rebuild when the compiler is updated 2020-05-12 13:28:33 +09:00
MAINTAINERS Power management updates for 5.10-rc1 2020-10-14 10:45:41 -07:00
Makefile Revert "kbuild: disable clang's default use of -fmerge-all-constants" 2020-10-13 18:38:26 -07:00
README Drop all 00-INDEX files from Documentation/ 2018-09-09 15:08:58 -06:00

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.