linux.git/drivers/cpufreq, branch v3.17-rc7

cpufreq: release policy->rwsem on error

2014-09-22T12:32:43+00:00

While debugging a cpufreq-related hardware failure on a system I saw the
following lockdep warning:

 =========================
 [ BUG: held lock freed! ] 3.17.0-rc4+ #1 Tainted: G            E
 -------------------------
 insmod/2247 is freeing memory ffff88006e1b1400-ffff88006e1b17ff, with a lock still held there!
  (&policy->rwsem){+.+...}, at: [] __cpufreq_add_dev.isra.21+0x47d/0xb80
 3 locks held by insmod/2247:
  #0:  (subsys mutex#5){+.+.+.}, at: [] subsys_interface_register+0x69/0x120
  #1:  (cpufreq_rwsem){.+.+.+}, at: [] __cpufreq_add_dev.isra.21+0x73/0xb80
  #2:  (&policy->rwsem){+.+...}, at: [] __cpufreq_add_dev.isra.21+0x47d/0xb80

 stack backtrace:
 CPU: 0 PID: 2247 Comm: insmod Tainted: G            E  3.17.0-rc4+ #1
 Hardware name: HP ProLiant MicroServer Gen8, BIOS J06 08/24/2013
  0000000000000000 000000008f3063c4 ffff88006f87bb30 ffffffff8171b358
  ffff88006bcf3750 ffff88006f87bb68 ffffffff810e09e1 ffff88006e1b1400
  ffffea0001b86c00 ffffffff8156d327 ffff880073003500 0000000000000246
 Call Trace:
  [] dump_stack+0x4d/0x66
  [] debug_check_no_locks_freed+0x171/0x180
  [] ? __cpufreq_add_dev.isra.21+0x427/0xb80
  [] kfree+0xab/0x2b0
  [] __cpufreq_add_dev.isra.21+0x427/0xb80
  [] ? _raw_spin_unlock+0x27/0x40
  [] ? pcc_cpufreq_do_osc+0x17f/0x17f [pcc_cpufreq]
  [] cpufreq_add_dev+0xe/0x10
  [] subsys_interface_register+0xc1/0x120
  [] cpufreq_register_driver+0x112/0x340
  [] ? kfree+0xda/0x2b0
  [] ? pcc_cpufreq_do_osc+0x17f/0x17f [pcc_cpufreq]
  [] pcc_cpufreq_init+0x4af/0xe81 [pcc_cpufreq]
  [] ? pcc_cpufreq_do_osc+0x17f/0x17f [pcc_cpufreq]
  [] do_one_initcall+0xd4/0x210
  [] ? __vunmap+0xd2/0x120
  [] load_module+0x1315/0x1b70
  [] ? store_uevent+0x70/0x70
  [] ? copy_module_from_fd.isra.44+0x129/0x180
  [] SyS_finit_module+0xa6/0xd0
  [] system_call_fastpath+0x16/0x1b
 cpufreq: __cpufreq_add_dev: ->get() failed
insmod: ERROR: could not insert module pcc-cpufreq.ko: No such device

The warning occurs in the __cpufreq_add_dev() code which does

        down_write(&policy->rwsem);
	...
        if (cpufreq_driver->get && !cpufreq_driver->setpolicy) {
                policy->cur = cpufreq_driver->get(policy->cpu);
                if (!policy->cur) {
                        pr_err("%s: ->get() failed\n", __func__);
                        goto err_get_freq;
                }

If cpufreq_driver->get(policy->cpu) returns an error we execute the
code at err_get_freq, which does not up the policy->rwsem.  This causes
the lockdep warning.

Trivial patch to up the policy->rwsem in the error path.

After the patch has been applied, and an error occurs in the
cpufreq_driver->get(policy->cpu) call we will now see

cpufreq: __cpufreq_add_dev: ->get() failed
cpufreq: __cpufreq_add_dev: ->get() failed
modprobe: ERROR: could not insert 'pcc_cpufreq': No such device

Fixes: 4e97b631f24c (cpufreq: Initialize governor for a new policy under policy->rwsem)
Signed-off-by: Prarit Bhargava 
Acked-by: Viresh Kumar 
Cc: 3.14+  # 3.14+
Signed-off-by: Rafael J. Wysocki

cpufreq: fix cpufreq suspend/resume for intel_pstate

2014-09-22T12:23:18+00:00

Cpufreq core introduces cpufreq_suspended flag to let cpufreq sysfs nodes
across S2RAM/S2DISK. But the flag is only set in the cpufreq_suspend()
for cpufreq drivers which have target or target_index callback. This
skips intel_pstate driver. This patch is to set the flag before checking
target or target_index callback.

Fixes: 2f0aea936360 (cpufreq: suspend governors on system suspend/hibernate)
Signed-off-by: Lan Tianyu 
Cc: 3.15+  # 3.15+
[rjw: Subject]
Signed-off-by: Rafael J. Wysocki

cpufreq / OPP: Fix the order of arguments for kcalloc()

2014-09-07T22:02:58+00:00

These changes fix the argument to the kcalloc
        @n: number of elements.
        @size: element size.
        @flags: the type of memory to allocate (see kmalloc).

        void *kcalloc(size_t n, size_t size, gfp_t flags)

Fixes: 3c5445ce3a0c (cpufreq: OPP: Avoid sleeping while atomic)
Signed-off-by: Anand Moon 
Acked-by: Viresh Kumar 
Reviewed-by: Stephen Boyd 
Signed-off-by: Rafael J. Wysocki

cpufreq: intel_pstate: Remove unneeded variable

2014-09-02T23:31:04+00:00

It should have been removed with commit d1b6848590af
("cpufreq / intel_pstate: Optimize intel_pstate_set_policy")

Signed-off-by: Gabriele Mazzotta 
Acked-by: Viresh Kumar 
Signed-off-by: Rafael J. Wysocki

cpufreq: s5pv210: Remove spurious __init annotation

2014-08-27T23:30:55+00:00

Since this is a platform driver and can be probed at any time we can't
annotate funtions in the probe path as __init, the code can't safely be
discarded at the end of kernel init.

Signed-off-by: Mark Brown 
Acked-by: Viresh Kumar 
Signed-off-by: Rafael J. Wysocki

cpufreq: intel_pstate: Add CPU ID for Braswell processor

2014-08-27T23:26:21+00:00

This is pretty much the same as Intel Baytrail, only the CPU ID is
different. Add the new ID to the supported CPU list.

Signed-off-by: Mika Westerberg 
Acked-by: Viresh Kumar 
Acked-by: Dirk Brandewie 
Signed-off-by: Rafael J. Wysocki

intel_pstate: Turn per cpu printk into pr_debug

2014-08-27T23:23:08+00:00

On larger systems intel_pstate currently spams the boot up
log with its "Intel pstate controlling ..." message for each CPU.
It's the only subsystem that prints a message for each
CPU.

Turn the message into a pr_debug.

Signed-off-by: Andi Kleen 
Acked-by: Dirk Brandewie 
Signed-off-by: Rafael J. Wysocki

Merge tag 'pm+acpi-3.17-rc1-2' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm

2014-08-15T00:13:46+00:00

Pull more ACPI and power management updates from Rafael Wysocki:
 "These are a couple of regression fixes, cpuidle menu governor
  optimizations, fixes for ACPI proccessor and battery drivers,
  hibernation fix to avoid problems related to the e820 memory map,
  fixes for a few cpufreq drivers and a new version of the suspend
  profiling tool analyze_suspend.py.

  Specifics:

   - Fix for an ACPI-based device hotplug regression introduced in 3.14
     that causes a kernel panic to trigger when memory hot-remove is
     attempted with CONFIG_ACPI_HOTPLUG_MEMORY unset from Tang Chen

   - Fix for a cpufreq regression introduced in 3.16 that triggers a
     "sleeping function called from invalid context" bug in
     dev_pm_opp_init_cpufreq_table() from Stephen Boyd

   - ACPI battery driver fix for a warning message added in 3.16 that
     prints silly stuff sometimes from Mariusz Ceier

   - Hibernation fix for safer handling of mismatches in the 820 memory
     map between the configurations during image creation and during the
     subsequent restore from Chun-Yi Lee

   - ACPI processor driver fix to handle CPU hotplug notifications
     correctly during system suspend/resume from Lan Tianyu

   - Series of four cpuidle menu governor cleanups that also should
     speed it up a bit from Mel Gorman

   - Fixes for the speedstep-smi, integrator, cpu0 and arm_big_little
     cpufreq drivers from Hans Wennborg, Himangi Saraogi, Markus
     Pargmann and Uwe Kleine-König

   - Version 3.0 of the analyze_suspend.py suspend profiling tool from
     Todd E Brandt"

* tag 'pm+acpi-3.17-rc1-2' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm:
  ACPI / battery: Fix warning message in acpi_battery_get_state()
  PM / tools: analyze_suspend.py: update to v3.0
  cpufreq: arm_big_little: fix module license spec
  cpufreq: speedstep-smi: fix decimal printf specifiers
  ACPI / hotplug: Check scan handlers in acpi_scan_hot_remove()
  cpufreq: OPP: Avoid sleeping while atomic
  cpufreq: cpu0: Do not print error message when deferring
  cpufreq: integrator: Use set_cpus_allowed_ptr
  PM / hibernate: avoid unsafe pages in e820 reserved regions
  ACPI / processor: Make acpi_cpu_soft_notify() process CPU FROZEN events
  cpuidle: menu: Lookup CPU runqueues less
  cpuidle: menu: Call nr_iowait_cpu less times
  cpuidle: menu: Use ktime_to_us instead of reinventing the wheel
  cpuidle: menu: Use shifts when calculating averages where possible

Merge tag 'devicetree-for-linus' of git://git.secretlab.ca/git/linux

2014-08-14T15:53:39+00:00

Pull device tree updates from Grant Likely:
 "The branch contains the following device tree changes the v3.17 merge
  window:

  Group changes to the device tree.  In preparation for adding device
  tree overlay support, OF_DYNAMIC is reworked so that a set of device
  tree changes can be prepared and applied to the tree all at once.
  OF_RECONFIG notifiers see the most significant change here so that
  users always get a consistent view of the tree.  Notifiers generation
  is moved from before a change to after it, and notifiers for a group
  of changes are emitted after the entire block of changes have been
  applied

  Automatic console selection from DT.  Console drivers can now use
  of_console_check() to see if the device node is specified as a console
  device.  If so then it gets added as a preferred console.  UART
  devices get this support automatically when uart_add_one_port() is
  called.

  DT unit tests no longer depend on pre-loaded data in the device tree.
  Data is loaded dynamically at the start of unit tests, and then
  unloaded again when the tests have completed.

  Also contains a few bugfixes for reserved regions and early memory
  setup"

* tag 'devicetree-for-linus' of git://git.secretlab.ca/git/linux: (21 commits)
  of: Fixing OF Selftest build error
  drivers: of: add automated assignment of reserved regions to client devices
  of: Use proper types for checking memory overflow
  of: typo fix in __of_prop_dup()
  Adding selftest testdata dynamically into live tree
  of: Add todo tasklist for Devicetree
  of: Transactional DT support.
  of: Reorder device tree changes and notifiers
  of: Move dynamic node fixups out of powerpc and into common code
  of: Make sure attached nodes don't carry along extra children
  of: Make devicetree sysfs update functions consistent.
  of: Create unlocked versions of node and property add/remove functions
  OF: Utility helper functions for dynamic nodes
  of: Move CONFIG_OF_DYNAMIC code into a separate file
  of: rename of_aliases_mutex to just of_mutex
  of/platform: Fix of_platform_device_destroy iteration of devices
  of: Migrate of_find_node_by_name() users to for_each_node_by_name()
  tty: Update hypervisor tty drivers to use core stdout parsing code.
  arm/versatile: Add the uart as the stdout device.
  of: Enable console on serial ports specified by /chosen/stdout-path
  ...

cpufreq: arm_big_little: fix module license spec

2014-08-09T00:43:33+00:00

Having no license specification in a module taints the kernel during load
with:

	arm_big_little: module license 'unspecified' taints kernel.

and also the linker doesn't allow it to make use of GPL-exported symbols
which in this case also results in errors like:

	arm_big_little: Unknown symbol cpufreq_register_driver (err 0)

. The header of the driver specifies a GPL v2 license, so note that
accordingly. While at it also add a description and an author and fix
the license in a companion file to explicit v2.

Reported-by: Andreas Schwab 
Acked-by: Viresh Kumar 
Signed-off-by: Uwe Kleine-König 
Signed-off-by: Rafael J. Wysocki