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Rafael J. Wysocki 53d7eed031 cpufreq: intel_pstate: Use HWP if enabled by platform firmware
commit e5af36b2adb858e982d78d41d7363d05d951a19a upstream.

It turns out that there are systems where HWP is enabled during
initialization by the platform firmware (BIOS), but HWP EPP support
is not advertised.

After commit 7aa1031223 ("cpufreq: intel_pstate: Avoid enabling HWP
if EPP is not supported") intel_pstate refuses to use HWP on those
systems, but the fallback PERF_CTL interface does not work on them
either because of enabled HWP, and once enabled, HWP cannot be
disabled.  Consequently, the users of those systems cannot control
CPU performance scaling.

Address this issue by making intel_pstate use HWP unconditionally if
it is enabled already when the driver starts.

Fixes: 7aa1031223 ("cpufreq: intel_pstate: Avoid enabling HWP if EPP is not supported")
Reported-by: Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com>
Tested-by: Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Cc: 5.9+ <stable@vger.kernel.org> # 5.9+
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-05-19 10:12:51 +02:00
arch KVM/VMX: Invoke NMI non-IST entry instead of IST entry 2021-05-19 10:12:51 +02:00
block block: return -EBUSY when there are open partitions in blkdev_reread_part 2021-04-28 13:39:59 +02:00
certs certs: Fix blacklist flag type confusion 2021-03-04 11:37:59 +01:00
crypto async_xor: increase src_offs when dropping destination page 2021-05-14 09:49:59 +02:00
Documentation media: docs: Fix data organization of MEDIA_BUS_FMT_RGB101010_1X30 2021-05-14 09:50:23 +02:00
drivers cpufreq: intel_pstate: Use HWP if enabled by platform firmware 2021-05-19 10:12:51 +02:00
fs afs: Fix speculative status fetches 2021-05-14 09:50:45 +02:00
include PM: runtime: Fix unpaired parent child_count for force_resume 2021-05-19 10:12:51 +02:00
init seccomp: Fix CONFIG tests for Seccomp_filters 2021-05-14 09:50:24 +02:00
ipc ipc: adjust proc_ipc_sem_dointvec definition to match prototype 2020-09-05 12:14:29 -07:00
kernel smp: Fix smp_call_function_single_async prototype 2021-05-14 09:50:46 +02:00
lib bug: Remove redundant condition check in report_bug 2021-05-14 09:50:32 +02:00
LICENSES LICENSES/deprecated: add Zlib license text 2020-09-16 14:33:49 +02:00
mm mm/memory-failure: unnecessary amount of unmapping 2021-05-14 09:50:45 +02:00
net sctp: delay auto_asconf init until binding the first addr 2021-05-14 09:50:46 +02:00
samples kfifo: fix ternary sign extension bugs 2021-05-14 09:50:45 +02:00
scripts kasan: fix hwasan build for gcc 2021-04-28 13:40:02 +02:00
security KEYS: trusted: Fix memory leak on object td 2021-05-19 10:12:50 +02:00
sound ALSA: usb: midi: don't return -ENOMEM when usb_urb_ep_type_check fails 2021-05-14 09:50:40 +02:00
tools perf session: Add swap operation for event TIME_CONV 2021-05-14 09:50:45 +02:00
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: Stop looking for coalesced MMIO zones if the bus is destroyed 2021-05-14 09:50:04 +02:00
.clang-format RDMA 5.10 pull request 2020-10-17 11:18:18 -07:00
.cocciconfig scripts: add Linux .cocciconfig for coccinelle 2016-07-22 12:13:39 +02:00
.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 mailmap: add two more addresses of Uwe Kleine-König 2020-12-06 10:19:07 -08:00
COPYING COPYING: state that all contributions really are covered by this file 2020-02-10 13:32:20 -08:00
CREDITS MAINTAINERS: Move Jason Cooper to CREDITS 2020-11-30 10:20:34 +01:00
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 MAINTAINERS: move the staging subsystem to lists.linux.dev 2021-03-25 09:04:18 +01:00
Makefile Linux 5.10.37 2021-05-14 09:50:46 +02:00
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.