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Chen Yu ba1edb9a51 ACPI: processor_perflib: Do not send _PPC change notification if not ready
The following warning was triggered after resumed from S3 -
if all the nonboot CPUs were put offline before suspend:

[ 1840.329515] unchecked MSR access error: RDMSR from 0x771 at rIP: 0xffffffff86061e3a (native_read_msr+0xa/0x30)
[ 1840.329516] Call Trace:
[ 1840.329521]  __rdmsr_on_cpu+0x33/0x50
[ 1840.329525]  generic_exec_single+0x81/0xb0
[ 1840.329527]  smp_call_function_single+0xd2/0x100
[ 1840.329530]  ? acpi_ds_result_pop+0xdd/0xf2
[ 1840.329532]  ? acpi_ds_create_operand+0x215/0x23c
[ 1840.329534]  rdmsrl_on_cpu+0x57/0x80
[ 1840.329536]  ? cpumask_next+0x1b/0x20
[ 1840.329538]  ? rdmsrl_on_cpu+0x57/0x80
[ 1840.329541]  intel_pstate_update_perf_limits+0xf3/0x220
[ 1840.329544]  ? notifier_call_chain+0x4a/0x70
[ 1840.329546]  intel_pstate_set_policy+0x4e/0x150
[ 1840.329548]  cpufreq_set_policy+0xcd/0x2f0
[ 1840.329550]  cpufreq_update_policy+0xb2/0x130
[ 1840.329552]  ? cpufreq_update_policy+0x130/0x130
[ 1840.329556]  acpi_processor_ppc_has_changed+0x65/0x80
[ 1840.329558]  acpi_processor_notify+0x80/0x100
[ 1840.329561]  acpi_ev_notify_dispatch+0x44/0x5c
[ 1840.329563]  acpi_os_execute_deferred+0x14/0x20
[ 1840.329565]  process_one_work+0x193/0x3c0
[ 1840.329567]  worker_thread+0x35/0x3b0
[ 1840.329569]  kthread+0x125/0x140
[ 1840.329571]  ? process_one_work+0x3c0/0x3c0
[ 1840.329572]  ? kthread_park+0x60/0x60
[ 1840.329575]  ? do_syscall_64+0x67/0x180
[ 1840.329577]  ret_from_fork+0x25/0x30
[ 1840.329585] unchecked MSR access error: WRMSR to 0x774 (tried to write 0x0000000000000000) at rIP: 0xffffffff86061f78 (native_write_msr+0x8/0x30)
[ 1840.329586] Call Trace:
[ 1840.329587]  __wrmsr_on_cpu+0x37/0x40
[ 1840.329589]  generic_exec_single+0x81/0xb0
[ 1840.329592]  smp_call_function_single+0xd2/0x100
[ 1840.329594]  ? acpi_ds_create_operand+0x215/0x23c
[ 1840.329595]  ? cpumask_next+0x1b/0x20
[ 1840.329597]  wrmsrl_on_cpu+0x57/0x70
[ 1840.329598]  ? rdmsrl_on_cpu+0x57/0x80
[ 1840.329599]  ? wrmsrl_on_cpu+0x57/0x70
[ 1840.329602]  intel_pstate_hwp_set+0xd3/0x150
[ 1840.329604]  intel_pstate_set_policy+0x119/0x150
[ 1840.329606]  cpufreq_set_policy+0xcd/0x2f0
[ 1840.329607]  cpufreq_update_policy+0xb2/0x130
[ 1840.329610]  ? cpufreq_update_policy+0x130/0x130
[ 1840.329613]  acpi_processor_ppc_has_changed+0x65/0x80
[ 1840.329615]  acpi_processor_notify+0x80/0x100
[ 1840.329617]  acpi_ev_notify_dispatch+0x44/0x5c
[ 1840.329619]  acpi_os_execute_deferred+0x14/0x20
[ 1840.329620]  process_one_work+0x193/0x3c0
[ 1840.329622]  worker_thread+0x35/0x3b0
[ 1840.329624]  kthread+0x125/0x140
[ 1840.329625]  ? process_one_work+0x3c0/0x3c0
[ 1840.329626]  ? kthread_park+0x60/0x60
[ 1840.329628]  ? do_syscall_64+0x67/0x180
[ 1840.329631]  ret_from_fork+0x25/0x30

This is because if there's only one online CPU, the MSR_PM_ENABLE
(package wide)can not be enabled after resumed, due to
intel_pstate_hwp_enable() will only be invoked on AP's online
process after resumed - if there's no AP online, the HWP remains
disabled after resumed (BIOS has disabled it in S3). Then if
there comes a _PPC change notification which touches HWP register
during this stage, the warning is triggered.

Since we don't call acpi_processor_register_performance() when
HWP is enabled, the pr->performance will be NULL. When this is
NULL we don't need to do _PPC change notification.

Reported-by: Doug Smythies <dsmythies@telus.net>
Suggested-by: Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com>
Signed-off-by: Yu Chen <yu.c.chen@intel.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2018-02-04 09:14:50 +01:00
Documentation ACPI updates for v4.16-rc1 2018-01-29 10:17:53 -08:00
arch ACPI updates for v4.16-rc1 2018-01-29 10:17:53 -08:00
block block: drain queue before waiting for q_usage_counter becoming zero 2018-01-05 09:09:48 -07:00
certs License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
crypto Merge branch 'linus' of git://git.kernel.org/pub/scm/linux/kernel/git/herbert/crypto-2.6 2018-01-12 09:47:58 -08:00
drivers ACPI: processor_perflib: Do not send _PPC change notification if not ready 2018-02-04 09:14:50 +01:00
firmware kbuild: remove all dummy assignments to obj- 2017-11-18 11:46:06 +09:00
fs orangefs: fix deadlock; do not write i_size in read_iter 2018-01-25 17:26:24 -08:00
include ACPI updates for v4.16-rc1 2018-01-29 10:17:53 -08:00
init init_task out-of-lining 2018-01-29 09:08:34 -08:00
ipc Rename superblock flags (MS_xyz -> SB_xyz) 2017-11-27 13:05:09 -08:00
kernel Power management updates for v4.16-rc1 2018-01-29 09:47:41 -08:00
lib Merge git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf 2018-01-10 11:17:21 -05:00
mm mm, page_vma_mapped: Introduce pfn_in_hpage() 2018-01-22 12:15:57 -08:00
net VSOCK: set POLLOUT | POLLWRNORM for TCP_CLOSING 2018-01-26 11:16:27 -05:00
samples Merge git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf 2017-12-03 13:08:30 -05:00
scripts scripts/gdb/linux/tasks.py: fix get_thread_info 2018-01-19 10:09:41 -08:00
security Merge branch 'x86-pti-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2018-01-14 09:51:25 -08:00
sound ALSA: hda - Reduce the suspend time consumption for ALC256 2018-01-19 14:18:34 +01:00
tools ACPI updates for v4.16-rc1 2018-01-29 10:17:53 -08:00
usr initramfs: fix initramfs rebuilds w/ compression after disabling 2017-11-03 07:39:19 -07:00
virt KVM/ARM Fixes for v4.15, Round 3 (v2) 2018-01-17 14:59:27 +01:00
.cocciconfig
.get_maintainer.ignore
.gitattributes .gitattributes: set git diff driver for C source code files 2016-10-07 18:46:30 -07:00
.gitignore Kbuild misc updates for v4.15 2017-11-17 17:51:33 -08:00
.mailmap mailmap: update Mark Yao's email address 2018-01-04 16:45:09 -08:00
COPYING
CREDITS MAINTAINERS: update TPM driver infrastructure changes 2017-11-09 17:58:40 -08:00
Kbuild Kbuild updates for v4.15 2017-11-17 17:45:29 -08:00
Kconfig License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
MAINTAINERS ACPI updates for v4.16-rc1 2018-01-29 10:17:53 -08:00
Makefile Linux 4.15 2018-01-28 13:20:33 -08:00
README README: add a new README file, pointing to the Documentation/ 2016-10-24 08:12:35 -02:00

README

Linux kernel
============

This file was moved to Documentation/admin-guide/README.rst

Please notice that there are several guides for kernel developers and users.
These guides can be rendered in a number of formats, like HTML and PDF.

In order to build the documentation, use ``make htmldocs`` or
``make pdfdocs``.

There are various text files in the Documentation/ subdirectory,
several of them using the Restructured Text markup notation.
See Documentation/00-INDEX for a list of what is contained in each file.

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.