linux-toradex.git/drivers/acpi/cppc_acpi.c, branch v4.16 Linux kernel for Apalis and Colibri modules ACPI / CPPC: Use 64-bit arithmetic instead of 32-bit 2018-02-07T10:15:02+00:00 Gustavo A. R. Silva gustavo@embeddedor.com 2018-02-06T23:36:17+00:00 b52f451105020677cad61a13b3b67af3fdedb91f Add suffix ULL to constant 500 in order to give the compiler complete information about the proper arithmetic to use. Notice that this constant is used in a context that expects an expression of type u64 (64 bits, unsigned). The expression NUM_RETRIES * cppc_ss->latency at line 578, which at preprocessing time translates to 500 * cppc_ss->latency is currently being evaluated using 32-bit arithmetic. Signed-off-by: Gustavo A. R. Silva <gustavo@embeddedor.com> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> 
Add suffix ULL to constant 500 in order to give the compiler complete
information about the proper arithmetic to use. Notice that this
constant is used in a context that expects an expression of type
u64 (64 bits, unsigned).

The expression NUM_RETRIES * cppc_ss->latency at line 578, which at
preprocessing time translates to 500 * cppc_ss->latency is currently
being evaluated using 32-bit arithmetic.

Signed-off-by: Gustavo A. R. Silva <gustavo@embeddedor.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
ACPI: CPPC: remove initial assignment of pcc_ss_data 2017-12-18T11:10:37+00:00 Colin Ian King colin.king@canonical.com 2017-12-08T23:59:49+00:00 951ef0e19f0736b45d1c4d81f4dfa04a43f87df5 The initialization of pcc_ss_data from pcc_data[pcc_ss_id] before pcc_ss_id is being range checked could lead to an out-of-bounds array read. This very same initialization is also being performed after the range check on pcc_ss_id, so we can just remove this problematic and also redundant assignment to fix the issue. Detected by cppcheck: warning: Value stored to 'pcc_ss_data' during its initialization is never read Fixes: 85b1407bf6d2 (ACPI / CPPC: Make CPPC ACPI driver aware of PCC subspace IDs) Signed-off-by: Colin Ian King <colin.king@canonical.com> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> 
The initialization of pcc_ss_data from pcc_data[pcc_ss_id] before
pcc_ss_id is being range checked could lead to an out-of-bounds array
read.  This very same initialization is also being performed after
the range check on pcc_ss_id, so we can just remove this problematic
and also redundant assignment to fix the issue.

Detected by cppcheck:
warning: Value stored to 'pcc_ss_data' during its initialization is never
read

Fixes: 85b1407bf6d2 (ACPI / CPPC: Make CPPC ACPI driver aware of PCC subspace IDs)
Signed-off-by: Colin Ian King <colin.king@canonical.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
ACPI / CPPC: Fix KASAN global out of bounds warning 2017-12-05T22:25:49+00:00 George Cherian george.cherian@cavium.com 2017-12-04T14:06:54+00:00 1ecbd7170d6579a1ee389a37bf1f0437ea01a388 Default value of pcc_subspace_idx is -1. Make sure to check pcc_subspace_idx before using the same as array index. This will avoid following KASAN warnings too. [ 15.113449] ================================================================== [ 15.116983] BUG: KASAN: global-out-of-bounds in cppc_get_perf_caps+0xf3/0x3b0 [ 15.116983] Read of size 8 at addr ffffffffb9a5c0d8 by task swapper/0/1 [ 15.116983] CPU: 3 PID: 1 Comm: swapper/0 Not tainted 4.15.0-rc2+ #2 [ 15.116983] Hardware name: Dell Inc. OptiPlex 7040/0Y7WYT, BIOS 1.2.8 01/26/2016 [ 15.116983] Call Trace: [ 15.116983] dump_stack+0x7c/0xbb [ 15.116983] print_address_description+0x1df/0x290 [ 15.116983] kasan_report+0x28a/0x370 [ 15.116983] ? cppc_get_perf_caps+0xf3/0x3b0 [ 15.116983] cppc_get_perf_caps+0xf3/0x3b0 [ 15.116983] ? cpc_read+0x210/0x210 [ 15.116983] ? __rdmsr_on_cpu+0x90/0x90 [ 15.116983] ? rdmsrl_on_cpu+0xa9/0xe0 [ 15.116983] ? rdmsr_on_cpu+0x100/0x100 [ 15.116983] ? wrmsrl_on_cpu+0x9c/0xd0 [ 15.116983] ? wrmsrl_on_cpu+0x9c/0xd0 [ 15.116983] ? wrmsr_on_cpu+0xe0/0xe0 [ 15.116983] __intel_pstate_cpu_init.part.16+0x3a2/0x530 [ 15.116983] ? intel_pstate_init_cpu+0x197/0x390 [ 15.116983] ? show_no_turbo+0xe0/0xe0 [ 15.116983] ? __lockdep_init_map+0xa0/0x290 [ 15.116983] intel_pstate_cpu_init+0x30/0x60 [ 15.116983] cpufreq_online+0x155/0xac0 [ 15.116983] cpufreq_add_dev+0x9b/0xb0 [ 15.116983] subsys_interface_register+0x1ae/0x290 [ 15.116983] ? bus_unregister_notifier+0x40/0x40 [ 15.116983] ? mark_held_locks+0x83/0xb0 [ 15.116983] ? _raw_write_unlock_irqrestore+0x32/0x60 [ 15.116983] ? intel_pstate_setup+0xc/0x104 [ 15.116983] ? intel_pstate_setup+0xc/0x104 [ 15.116983] ? cpufreq_register_driver+0x1ce/0x2b0 [ 15.116983] cpufreq_register_driver+0x1ce/0x2b0 [ 15.116983] ? intel_pstate_setup+0x104/0x104 [ 15.116983] intel_pstate_register_driver+0x3a/0xa0 [ 15.116983] intel_pstate_init+0x3c4/0x434 [ 15.116983] ? intel_pstate_setup+0x104/0x104 [ 15.116983] ? intel_pstate_setup+0x104/0x104 [ 15.116983] do_one_initcall+0x9c/0x206 [ 15.116983] ? parameq+0xa0/0xa0 [ 15.116983] ? initcall_blacklisted+0x150/0x150 [ 15.116983] ? lock_downgrade+0x2c0/0x2c0 [ 15.116983] kernel_init_freeable+0x327/0x3f0 [ 15.116983] ? start_kernel+0x612/0x612 [ 15.116983] ? _raw_spin_unlock_irq+0x29/0x40 [ 15.116983] ? finish_task_switch+0xdd/0x320 [ 15.116983] ? finish_task_switch+0x8e/0x320 [ 15.116983] ? rest_init+0xd0/0xd0 [ 15.116983] kernel_init+0xf/0x11a [ 15.116983] ? rest_init+0xd0/0xd0 [ 15.116983] ret_from_fork+0x24/0x30 [ 15.116983] The buggy address belongs to the variable: [ 15.116983] __key.36299+0x38/0x40 [ 15.116983] Memory state around the buggy address: [ 15.116983] ffffffffb9a5bf80: fa fa fa fa 00 fa fa fa fa fa fa fa 00 fa fa fa [ 15.116983] ffffffffb9a5c000: fa fa fa fa 00 fa fa fa fa fa fa fa 00 fa fa fa [ 15.116983] >ffffffffb9a5c080: fa fa fa fa 00 fa fa fa fa fa fa fa 00 00 00 00 [ 15.116983] ^ [ 15.116983] ffffffffb9a5c100: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 [ 15.116983] ffffffffb9a5c180: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 [ 15.116983] ================================================================== Fixes: 85b1407bf6d2 (ACPI / CPPC: Make CPPC ACPI driver aware of PCC subspace IDs) Reported-by: Changbin Du <changbin.du@intel.com> Signed-off-by: George Cherian <george.cherian@cavium.com> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> 
Default value of pcc_subspace_idx is -1.
Make sure to check pcc_subspace_idx before using the same as array index.
This will avoid following KASAN warnings too.

[   15.113449] ==================================================================
[   15.116983] BUG: KASAN: global-out-of-bounds in cppc_get_perf_caps+0xf3/0x3b0
[   15.116983] Read of size 8 at addr ffffffffb9a5c0d8 by task swapper/0/1
[   15.116983] CPU: 3 PID: 1 Comm: swapper/0 Not tainted 4.15.0-rc2+ #2
[   15.116983] Hardware name: Dell Inc. OptiPlex 7040/0Y7WYT, BIOS 1.2.8 01/26/2016
[   15.116983] Call Trace:
[   15.116983]  dump_stack+0x7c/0xbb
[   15.116983]  print_address_description+0x1df/0x290
[   15.116983]  kasan_report+0x28a/0x370
[   15.116983]  ? cppc_get_perf_caps+0xf3/0x3b0
[   15.116983]  cppc_get_perf_caps+0xf3/0x3b0
[   15.116983]  ? cpc_read+0x210/0x210
[   15.116983]  ? __rdmsr_on_cpu+0x90/0x90
[   15.116983]  ? rdmsrl_on_cpu+0xa9/0xe0
[   15.116983]  ? rdmsr_on_cpu+0x100/0x100
[   15.116983]  ? wrmsrl_on_cpu+0x9c/0xd0
[   15.116983]  ? wrmsrl_on_cpu+0x9c/0xd0
[   15.116983]  ? wrmsr_on_cpu+0xe0/0xe0
[   15.116983]  __intel_pstate_cpu_init.part.16+0x3a2/0x530
[   15.116983]  ? intel_pstate_init_cpu+0x197/0x390
[   15.116983]  ? show_no_turbo+0xe0/0xe0
[   15.116983]  ? __lockdep_init_map+0xa0/0x290
[   15.116983]  intel_pstate_cpu_init+0x30/0x60
[   15.116983]  cpufreq_online+0x155/0xac0
[   15.116983]  cpufreq_add_dev+0x9b/0xb0
[   15.116983]  subsys_interface_register+0x1ae/0x290
[   15.116983]  ? bus_unregister_notifier+0x40/0x40
[   15.116983]  ? mark_held_locks+0x83/0xb0
[   15.116983]  ? _raw_write_unlock_irqrestore+0x32/0x60
[   15.116983]  ? intel_pstate_setup+0xc/0x104
[   15.116983]  ? intel_pstate_setup+0xc/0x104
[   15.116983]  ? cpufreq_register_driver+0x1ce/0x2b0
[   15.116983]  cpufreq_register_driver+0x1ce/0x2b0
[   15.116983]  ? intel_pstate_setup+0x104/0x104
[   15.116983]  intel_pstate_register_driver+0x3a/0xa0
[   15.116983]  intel_pstate_init+0x3c4/0x434
[   15.116983]  ? intel_pstate_setup+0x104/0x104
[   15.116983]  ? intel_pstate_setup+0x104/0x104
[   15.116983]  do_one_initcall+0x9c/0x206
[   15.116983]  ? parameq+0xa0/0xa0
[   15.116983]  ? initcall_blacklisted+0x150/0x150
[   15.116983]  ? lock_downgrade+0x2c0/0x2c0
[   15.116983]  kernel_init_freeable+0x327/0x3f0
[   15.116983]  ? start_kernel+0x612/0x612
[   15.116983]  ? _raw_spin_unlock_irq+0x29/0x40
[   15.116983]  ? finish_task_switch+0xdd/0x320
[   15.116983]  ? finish_task_switch+0x8e/0x320
[   15.116983]  ? rest_init+0xd0/0xd0
[   15.116983]  kernel_init+0xf/0x11a
[   15.116983]  ? rest_init+0xd0/0xd0
[   15.116983]  ret_from_fork+0x24/0x30

[   15.116983] The buggy address belongs to the variable:
[   15.116983]  __key.36299+0x38/0x40

[   15.116983] Memory state around the buggy address:
[   15.116983]  ffffffffb9a5bf80: fa fa fa fa 00 fa fa fa fa fa fa fa 00 fa fa fa
[   15.116983]  ffffffffb9a5c000: fa fa fa fa 00 fa fa fa fa fa fa fa 00 fa fa fa
[   15.116983] >ffffffffb9a5c080: fa fa fa fa 00 fa fa fa fa fa fa fa 00 00 00 00
[   15.116983]                                                     ^
[   15.116983]  ffffffffb9a5c100: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
[   15.116983]  ffffffffb9a5c180: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
[   15.116983] ==================================================================

Fixes: 85b1407bf6d2 (ACPI / CPPC: Make CPPC ACPI driver aware of PCC subspace IDs)
Reported-by: Changbin Du <changbin.du@intel.com>
Signed-off-by: George Cherian <george.cherian@cavium.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
ACPI / CPPC: Make CPPC ACPI driver aware of PCC subspace IDs 2017-11-08T23:39:54+00:00 George Cherian george.cherian@cavium.com 2017-10-11T08:54:58+00:00 85b1407bf6d2f4a1583e9201b8c163703df733cc Based on ACPI 6.2 Section 8.4.7.1.9 If the PCC register space is used, all PCC registers, for all processors in the same performance domain (as defined by _PSD), must be defined to be in the same subspace. Based on Section 14.1 of ACPI specification, it is possible to have a maximum of 256 PCC subspace IDs. Add support of multiple PCC subspace ID instead of using a single global pcc_data structure. While at that, fix the time_delta check in send_pcc_cmd() so that last_mpar_reset and mpar_count are initialized properly. Signed-off-by: George Cherian <george.cherian@cavium.com> Reviewed-by: Prashanth Prakash <pprakash@codeaurora.org> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> 
Based on ACPI 6.2 Section 8.4.7.1.9 If the PCC register space is used,
all PCC registers, for all processors in the same performance domain
(as defined by _PSD), must be defined to be in the same subspace.

Based on Section 14.1 of ACPI specification, it is possible to have a
maximum of 256 PCC subspace IDs. Add support of multiple PCC subspace
ID instead of using a single global pcc_data structure.

While at that, fix the time_delta check in send_pcc_cmd() so that
last_mpar_reset and mpar_count are initialized properly.

Signed-off-by: George Cherian <george.cherian@cavium.com>
Reviewed-by: Prashanth Prakash <pprakash@codeaurora.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
scripts/spelling.txt: add regsiter -> register spelling mistake 2017-05-09T00:15:13+00:00 Stephen Boyd sboyd@codeaurora.org 2017-05-08T22:57:50+00:00 ad61dd303a0f2439bb104349e2d2ec91a3010ce0 This typo is quite common. Fix it and add it to the spelling file so that checkpatch catches it earlier. Link: http://lkml.kernel.org/r/20170317011131.6881-2-sboyd@codeaurora.org Signed-off-by: Stephen Boyd <sboyd@codeaurora.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> 
This typo is quite common.  Fix it and add it to the spelling file so
that checkpatch catches it earlier.

Link: http://lkml.kernel.org/r/20170317011131.6881-2-sboyd@codeaurora.org
Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
ACPI / CPPC: add sysfs entries for CPPC perf capabilities 2017-04-18T21:37:50+00:00 Prakash, Prashanth pprakash@codeaurora.org 2017-03-29T19:50:00+00:00 2c74d8473d19c159a3c3eabaa4819e110c97e8ec Computed delivered performance using CPPC feedback counters are in the CPPC abstract scale, whereas cppc_cpufreq driver operates in KHz scale. Exposing the CPPC performance capabilities (highest,lowest, nominal, lowest non-linear) will allow userspace to figure out the conversion factor from CPPC abstract scale to KHz. Also rename ctr_wrap_time to wraparound_time so that show_cppc_data() macro will work with it. Signed-off-by: Prashanth Prakash <pprakash@codeaurora.org> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> 
Computed delivered performance using CPPC feedback counters are in the
CPPC abstract scale, whereas cppc_cpufreq driver operates in KHz scale.
Exposing the CPPC performance capabilities (highest,lowest, nominal,
lowest non-linear) will allow userspace to figure out the conversion
factor from CPPC abstract scale to KHz.

Also rename ctr_wrap_time to wraparound_time so that show_cppc_data()
macro will work with it.

Signed-off-by: Prashanth Prakash <pprakash@codeaurora.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
ACPI / CPPC: Read lowest nonlinear perf in cppc_get_perf_caps() 2017-04-18T21:37:49+00:00 Prakash, Prashanth pprakash@codeaurora.org 2017-03-29T19:49:59+00:00 368520a6b2dd232ea5743a6acd9f056bc30e05b4 Read lowest non linear perf in cppc_get_perf_caps so that it can be exposed via sysfs to the usespace. Lowest non linear perf is the lowest performance level at which nonlinear power savings are achieved. Signed-off-by: Prashanth Prakash <pprakash@codeaurora.org> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> 
Read lowest non linear perf in cppc_get_perf_caps so that it can be exposed
via sysfs to the usespace. Lowest non linear perf is the lowest performance
level at which nonlinear power savings are achieved.

Signed-off-by: Prashanth Prakash <pprakash@codeaurora.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
ACPI / CPPC: Fix per-CPU pointer management in acpi_cppc_processor_probe() 2016-12-12T22:52:34+00:00 Rafael J. Wysocki rafael.j.wysocki@intel.com 2016-12-09T23:52:28+00:00 28076483afac9dd77df269f5d460e51a09dfb19f Fix a possible use-after-free scenario in acpi_cppc_processor_probe() that can happen if the function returns without cleaning up the per-CPU pointer set by it previously. Reported-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> 
Fix a possible use-after-free scenario in acpi_cppc_processor_probe()
that can happen if the function returns without cleaning up the
per-CPU pointer set by it previously.

Reported-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
ACPI / CPPC: Fix crash in acpi_cppc_processor_exit() 2016-12-12T22:51:36+00:00 Sebastian Andrzej Siewior bigeasy@linutronix.de 2016-12-07T19:06:08+00:00 9e9d68dad58c70f40f50adfeabd2fdaa39a743fd First I had crashed what I bisected down to de966cf4a4fa (sched/x86: Change CONFIG_SCHED_ITMT to CONFIG_SCHED_MC_PRIO) because it made SCHED_ITMT the default. Then I run another bisect round and got here with the same backtrace: |BUG: unable to handle kernel NULL pointer dereference at (null) |IP: [<ffffffff812aab6e>] acpi_cppc_processor_exit+0x40/0x60 |PGD 0 [ 0.577616] |Oops: 0000 [#1] SMP |Modules linked in: |CPU: 3 PID: 1 Comm: swapper/0 Not tainted 4.9.0-rc6-00146-g17669006adf6 #51 |task: ffff88003f878000 task.stack: ffffc90000008000 |RIP: 0010:[<ffffffff812aab6e>] [<ffffffff812aab6e>] acpi_cppc_processor_exit+0x40/0x60 |RSP: 0000:ffffc9000000bd48 EFLAGS: 00010296 |RAX: 00000000000137e0 RBX: 0000000000000000 RCX: 0000000000000001 |RDX: ffff88003fc00000 RSI: 0000000000000000 RDI: ffff88003fbca130 |RBP: ffffc9000000bd60 R08: 0000000000000514 R09: 0000000000000000 |R10: 0000000000000001 R11: 0000000000000000 R12: 0000000000000002 |R13: 0000000000000020 R14: ffffffff8167cb00 R15: 0000000000000000 |FS: 0000000000000000(0000) GS:ffff88003fcc0000(0000) knlGS:0000000000000000 |CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 |CR2: 0000000000000000 CR3: 0000000001618000 CR4: 00000000000406e0 |Stack: | ffff88003f939848 ffff88003fbca130 0000000000000001 ffffc9000000bd80 | ffffffff812a4ccb ffff88003fc0cee8 0000000000000000 ffffc9000000bdb8 | ffffffff812dc20d ffff88003fc0cee8 ffffffff8167cb00 ffff88003fc0cf48 |Call Trace: | [<ffffffff812a4ccb>] acpi_processor_stop+0xb2/0xc5 | [<ffffffff812dc20d>] driver_probe_device+0x14d/0x2f0 | [<ffffffff812dc41e>] __driver_attach+0x6e/0x90 | [<ffffffff812da234>] bus_for_each_dev+0x54/0x90 | [<ffffffff812dbbf9>] driver_attach+0x19/0x20 | [<ffffffff812db6a6>] bus_add_driver+0xe6/0x200 | [<ffffffff812dcb23>] driver_register+0x83/0xc0 | [<ffffffff816f050a>] acpi_processor_driver_init+0x20/0x94 | [<ffffffff81000487>] do_one_initcall+0x97/0x180 | [<ffffffff816ccf5c>] kernel_init_freeable+0x112/0x1a6 | [<ffffffff813a0fc9>] kernel_init+0x9/0xf0 | [<ffffffff813acf35>] ret_from_fork+0x25/0x30 |Code: 02 00 00 00 48 8b 14 d5 e0 c3 55 81 48 8b 1c 02 4c 8d 6b 20 eb 15 49 8b 7d 00 48 85 ff 74 05 e8 39 8c d9 ff 41 ff c4 49 83 c5 20 <44> 3b 23 72 e6 48 8d bb a0 02 00 00 e8 b1 6f f9 ff 48 89 df e8 |RIP [<ffffffff812aab6e>] acpi_cppc_processor_exit+0x40/0x60 | RSP <ffffc9000000bd48> |CR2: 0000000000000000 |---[ end trace 917a625107b09711 ]--- Fix it. Fixes: 17669006adf6 (cpufreq/intel_pstate: Use CPPC to get max performance) Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de> [ rjw: Subject ] Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> 
First I had crashed what I bisected down to de966cf4a4fa (sched/x86: Change
CONFIG_SCHED_ITMT to CONFIG_SCHED_MC_PRIO) because it made SCHED_ITMT the
default.

Then I run another bisect round and got here with the same backtrace:

|BUG: unable to handle kernel NULL pointer dereference at           (null)
|IP: [<ffffffff812aab6e>] acpi_cppc_processor_exit+0x40/0x60
|PGD 0 [    0.577616]
|Oops: 0000 [#1] SMP
|Modules linked in:
|CPU: 3 PID: 1 Comm: swapper/0 Not tainted 4.9.0-rc6-00146-g17669006adf6 #51
|task: ffff88003f878000 task.stack: ffffc90000008000
|RIP: 0010:[<ffffffff812aab6e>]  [<ffffffff812aab6e>] acpi_cppc_processor_exit+0x40/0x60
|RSP: 0000:ffffc9000000bd48  EFLAGS: 00010296
|RAX: 00000000000137e0 RBX: 0000000000000000 RCX: 0000000000000001
|RDX: ffff88003fc00000 RSI: 0000000000000000 RDI: ffff88003fbca130
|RBP: ffffc9000000bd60 R08: 0000000000000514 R09: 0000000000000000
|R10: 0000000000000001 R11: 0000000000000000 R12: 0000000000000002
|R13: 0000000000000020 R14: ffffffff8167cb00 R15: 0000000000000000
|FS:  0000000000000000(0000) GS:ffff88003fcc0000(0000) knlGS:0000000000000000
|CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
|CR2: 0000000000000000 CR3: 0000000001618000 CR4: 00000000000406e0
|Stack:
| ffff88003f939848 ffff88003fbca130 0000000000000001 ffffc9000000bd80
| ffffffff812a4ccb ffff88003fc0cee8 0000000000000000 ffffc9000000bdb8
| ffffffff812dc20d ffff88003fc0cee8 ffffffff8167cb00 ffff88003fc0cf48
|Call Trace:
| [<ffffffff812a4ccb>] acpi_processor_stop+0xb2/0xc5
| [<ffffffff812dc20d>] driver_probe_device+0x14d/0x2f0
| [<ffffffff812dc41e>] __driver_attach+0x6e/0x90
| [<ffffffff812da234>] bus_for_each_dev+0x54/0x90
| [<ffffffff812dbbf9>] driver_attach+0x19/0x20
| [<ffffffff812db6a6>] bus_add_driver+0xe6/0x200
| [<ffffffff812dcb23>] driver_register+0x83/0xc0
| [<ffffffff816f050a>] acpi_processor_driver_init+0x20/0x94
| [<ffffffff81000487>] do_one_initcall+0x97/0x180
| [<ffffffff816ccf5c>] kernel_init_freeable+0x112/0x1a6
| [<ffffffff813a0fc9>] kernel_init+0x9/0xf0
| [<ffffffff813acf35>] ret_from_fork+0x25/0x30
|Code: 02 00 00 00 48 8b 14 d5 e0 c3 55 81 48 8b 1c 02 4c 8d 6b 20 eb 15 49 8b 7d 00 48 85 ff 74 05 e8 39 8c d9 ff 41 ff c4 49 83 c5 20 <44> 3b 23 72 e6 48 8d bb a0 02 00 00 e8 b1 6f f9 ff 48 89 df e8
|RIP  [<ffffffff812aab6e>] acpi_cppc_processor_exit+0x40/0x60
| RSP <ffffc9000000bd48>
|CR2: 0000000000000000
|---[ end trace 917a625107b09711 ]---

Fix it.

Fixes: 17669006adf6 (cpufreq/intel_pstate: Use CPPC to get max performance)
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
[ rjw: Subject ]
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
ACPI / CPPC: set an error code on probe error path 2016-11-30T22:16:31+00:00 Dan Carpenter dan.carpenter@oracle.com 2016-11-30T19:22:54+00:00 501634759d55a5b56967de6d9465acf02bbc3565 We should return -EINVAL (instead of 0) if get_cpu_device() fails. Fixes: 158c998ea44b (ACPI / CPPC: add sysfs support to compute delivered performance) Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> 
We should return -EINVAL (instead of 0) if get_cpu_device() fails.

Fixes: 158c998ea44b (ACPI / CPPC: add sysfs support to compute delivered performance)
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>