Add perf trace event "power:pstate_sample" to report driver state to
aid in diagnosing issues reported against intel_pstate.
Signed-off-by: Dirk Brandewie <dirk.j.brandewie@intel.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
CPUFreq drivers that use clock frameworks interface,i.e. clk_get_rate(),
to get CPUs clk rate, have similar sort of code used in most of them.
This patch adds a generic ->get() which will do the same thing for them.
All those drivers are required to now is to set .get to cpufreq_generic_get()
and set their clk pointer in policy->clk during ->init().
Acked-by: Hans-Christian Egtvedt <egtvedt@samfundet.no>
Acked-by: Shawn Guo <shawn.guo@linaro.org>
Acked-by: Linus Walleij <linus.walleij@linaro.org>
Acked-by: Shawn Guo <shawn.guo@linaro.org>
Acked-by: Stephen Warren <swarren@nvidia.com>
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
There are some parts of common kernel which would be using routines
like clk_get_rate() on some platforms. Currently, they wouldn't be
called for SA1100 boards, but they are needed for successful kernel
compilation.
Create a dummy clk_get_rate() routine for SA1100 which can be called
by the cpufreq core. More dummy routines might be added later if
necessary.
Cc: Russell King <linux@arm.linux.org.uk>
Cc: Arnd Bergmann <arnd.bergmann@linaro.org>
Reported-by: Olof Johansson <olof@lixom.net>
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
[rjw: Changelog]
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
When cpufreq_stats is compiled in as a module, cpufreq driver would
have already been registered. And so the CPUFREQ_CREATE_POLICY
notifiers wouldn't be called for it. Hence no sysfs entries for stats. :(
This patch calls cpufreq_stats_create_table() for each online CPU from
cpufreq_stats_init() and so if policy is already created for CPUx then
we will register sysfs stats for it.
When its not compiled as module, we will return early as policy wouldn't
be found for any of the CPUs.
Acked-by: Nicolas Pitre <nico@linaro.org>
Tested-by: Nicolas Pitre <nico@linaro.org>
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
We don't have code paths now where we need to do these two things
separately, so it is better do them in a single routine. Just as
they are allocated in a single routine.
Acked-by: Nicolas Pitre <nico@linaro.org>
Tested-by: Nicolas Pitre <nico@linaro.org>
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Either CPUs are hot-unplugged or suspend/resume occurs, cpufreq core
will send notifications to cpufreq-stats and stats structure and sysfs
entries would be correctly handled..
And so we don't actually need hotcpu notifiers in cpufreq-stats anymore.
We were only handling cpu hot-unplug events here and that are already
taken care of by POLICY notifiers.
Acked-by: Nicolas Pitre <nico@linaro.org>
Tested-by: Nicolas Pitre <nico@linaro.org>
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
There are several problems with cpufreq stats in the way it handles
cpufreq_unregister_driver() and suspend/resume..
- We must not lose data collected so far when suspend/resume happens
and so stats directories must not be removed/allocated during these
operations, which is done currently.
- cpufreq_stat has registered notifiers with both cpufreq and hotplug.
It adds sysfs stats directory with a cpufreq notifier: CPUFREQ_NOTIFY
and removes this directory with a notifier from hotplug core.
In case cpufreq_unregister_driver() is called (on rmmod cpufreq driver),
stats directories per cpu aren't removed as CPUs are still online. The
only call cpufreq_stats gets is cpufreq_stats_update_policy_cpu() for
all CPUs except the last of each policy. And pointer to stat information
is stored in the entry for last CPU in the per-cpu cpufreq_stats_table.
But policy structure would be freed inside cpufreq core and so that will
result in memory leak inside cpufreq stats (as we are never freeing
memory for stats).
Now if we again insert the module cpufreq_register_driver() will be
called and we will again allocate stats data and put it on for first
CPU of every policy. In case we only have a single CPU per policy, we
will return with a error from cpufreq_stats_create_table() due to this
code:
if (per_cpu(cpufreq_stats_table, cpu))
return -EBUSY;
And so probably cpufreq stats directory would not show up anymore (as
it was added inside last policies->kobj which doesn't exist anymore).
I haven't tested it, though. Also the values in stats files wouldn't
be refreshed as we are using the earlier stats structure.
- CPUFREQ_NOTIFY is called from cpufreq_set_policy() which is called for
scenarios where we don't really want cpufreq_stat_notifier_policy() to get
called. For example whenever we are changing anything related to a policy:
min/max/current freq, etc. cpufreq_set_policy() is called and so cpufreq
stats is notified. Where we don't do any useful stuff other than simply
returning with -EBUSY from cpufreq_stats_create_table(). And so this
isn't the right notifier that cpufreq stats..
Due to all above reasons this patch does following changes:
- Add new notifiers CPUFREQ_CREATE_POLICY and CPUFREQ_REMOVE_POLICY,
which are only called when policy is created/destroyed. They aren't
called for suspend/resume paths..
- Use these notifiers in cpufreq_stat_notifier_policy() to create/destory
stats sysfs entries. And so cpufreq_unregister_driver() or suspend/resume
shouldn't be a problem for cpufreq_stats.
- Return early from cpufreq_stat_cpu_callback() for suspend/resume sequence,
so that we don't free stats structure.
Acked-by: Nicolas Pitre <nico@linaro.org>
Tested-by: Nicolas Pitre <nico@linaro.org>
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
The only caller of speedstep_get_state() was removed in commit d4019f0a92
("cpufreq: move freq change notifications to cpufreq core"). So building
speedstep-smi.o now triggers a GCC warning:
drivers/cpufreq/speedstep-smi.c:148:12: warning: 'speedstep_get_state' defined but not used [-Wunused-function]
Remove this unused function.
Signed-off-by: Paul Bolle <pebolle@tiscali.nl>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
This patch reorders reported frequencies from the highest to the lowest,
just like in other frequency drivers.
Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
The powernow-k6 driver used to read the initial multiplier from the
powernow register. However, there is a problem with this:
* If there was a frequency transition before, the multiplier read from the
register corresponds to the current multiplier.
* If there was no frequency transition since reset, the field in the
register always reads as zero, regardless of the current multiplier that
is set using switches on the mainboard and that the CPU is running at.
The zero value corresponds to multiplier 4.5, so as a consequence, the
powernow-k6 driver always assumes multiplier 4.5.
For example, if we have 550MHz CPU with bus frequency 100MHz and
multiplier 5.5, the powernow-k6 driver thinks that the multiplier is 4.5
and bus frequency is 122MHz. The powernow-k6 driver then sets the
multiplier to 4.5, underclocking the CPU to 450MHz, but reports the
current frequency as 550MHz.
There is no reliable way how to read the initial multiplier. I modified
the driver so that it contains a table of known frequencies (based on
parameters of existing CPUs and some common overclocking schemes) and sets
the multiplier according to the frequency. If the frequency is unknown
(because of unusual overclocking or underclocking), the user must supply
the bus speed and maximum multiplier as module parameters.
This patch should be backported to all stable kernels. If it doesn't
apply cleanly, change it, or ask me to change it.
Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
I found out that a system with k6-3+ processor is unstable during network
server load. The system locks up or the network card stops receiving. The
reason for the instability is the CPU frequency scaling.
During frequency transition the processor is in "EPM Stop Grant" state.
The documentation says that the processor doesn't respond to inquiry
requests in this state. Consequently, coherency of processor caches and
bus master devices is not maintained, causing the system instability.
This patch flushes the cache during frequency transition. It fixes the
instability.
Other minor changes:
* u64 invalue changed to unsigned long because the variable is 32-bit
* move the logic to set the multiplier to a separate function
powernow_k6_set_cpu_multiplier
* preserve lower 5 bits of the powernow port instead of 4 (the voltage
field has 5 bits)
* mask interrupts when reading the multiplier, so that the port is not
open during other activity (running other kernel code with the port open
shouldn't cause any misbehavior, but we should better be safe and keep
the port closed)
This patch should be backported to all stable kernels. If it doesn't
apply cleanly, change it, or ask me to change it.
Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Add a Documentation/ABI entry for
/sys/devices/system/cpu/intel_pstate/max_perf_pct,
/sys/devices/system/cpu/intel_pstate/min_perf_pct, and
/sys/devices/system/cpu/intel_pstate/no_turbo.
Cc: Dirk Brandewie <dirk.brandewie@gmail.com>
Cc: Randy Dunlap <rdunlap@infradead.org>
Signed-off-by: Ramkumar Ramachandra <artagnon@gmail.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Sometimes boot loaders set CPU frequency to a value outside of frequency table
present with cpufreq core. In such cases CPU might be unstable if it has to run
on that frequency for long duration of time and so its better to set it to a
frequency which is specified in freq-table. This also makes cpufreq stats
inconsistent as cpufreq-stats would fail to register because current frequency
of CPU isn't found in freq-table.
Because we don't want this change to affect boot process badly, we go for the
next freq which is >= policy->cur ('cur' must be set by now, otherwise we will
end up setting freq to lowest of the table as 'cur' is initialized to zero).
In case current frequency doesn't match any frequency from freq-table, we throw
warnings to user, so that user can get this fixed in their bootloaders or
freq-tables.
Reported-by: Carlos Hernandez <ceh@ti.com>
Reported-and-tested-by: Nishanth Menon <nm@ti.com>
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Sometimes boot loaders set CPU frequency to a value outside of frequency table
present with cpufreq core. In such cases CPU might be unstable if it has to run
on that frequency for long duration of time and so its better to set it to a
frequency which is specified in frequency table.
On some systems we can't really say what frequency we're running at the moment
and so for these we shouldn't check if we are running at a frequency present in
frequency table. And so we really can't force this for all the cpufreq drivers.
Hence we are created another flag here: CPUFREQ_NEED_INITIAL_FREQ_CHECK that
will be marked by platforms which want to go for this check at boot time.
Initially this is done for all ARM platforms but others may follow if required.
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Add a routine check to see if the platform supplied the OPP table.
Incase there's no OPP table exist, it will try to initialise it.
It's been tested on iMX6SL board where the platform doesn't have
an OPP table.
Signed-off-by: John Tobias <john.tobias.ph@gmail.com>
Acked-by: Shawn Guo <shawn.guo@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
The imx6q-cpufreq driver nowadays is not only running on imx6q but also
other i.MX6 series SoCs like imx6dl and imx6sl. Update Kconfig prompt
and help text to make it clear to users.
Signed-off-by: Shawn Guo <shawn.guo@linaro.org>
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
on i.MX6Q, cpu freq change need to follow below flows:
1. each setpoint has different VDDARM, VDDSOC/PU voltage, get the setpoint
table from dts;
2. when cpu freq is scaling up, need to increase VDDSOC/PU voltage before
VDDARM, if VDDPU is off, no need to change it;
3. when cpu freq is scaling down, need to decrease VDDARM voltage before
VDDSOC/PU, if VDDPU is off, no need to change it;
normally dts will pass vddsoc/pu freq/volt info to kernel, if not, will
use fixed value for vddsoc/pu voltage setting.
Signed-off-by: Anson Huang <b20788@freescale.com>
Acked-by: Shawn Guo <shawn.guo@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
In the current code, if we fail during a frequency transition, we
simply send the POSTCHANGE notification with the old frequency. This
isn't enough.
One of the core users of these notifications is the code responsible
for keeping loops_per_jiffy aligned with frequency changes. And mostly
it is written as:
if ((val == CPUFREQ_PRECHANGE && freq->old < freq->new) ||
(val == CPUFREQ_POSTCHANGE && freq->old > freq->new)) {
update-loops-per-jiffy...
}
So, suppose we are changing to a higher frequency and failed during
transition, then following will happen:
- CPUFREQ_PRECHANGE notification with freq-new > freq-old
- CPUFREQ_POSTCHANGE notification with freq-new == freq-old
The first one will update loops_per_jiffy and second one will do
nothing. Even if we send the 2nd notification by exchanging values of
freq-new and old, some users of these notifications might get
unstable.
This can be fixed by simply calling cpufreq_notify_post_transition()
with error code and this routine will take care of sending
notifications in the correct order.
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
[rjw: Folded 3 patches into one, rebased unicore2 changes]
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
This introduces a new routine cpufreq_notify_post_transition() which
can be used to send POSTCHANGE notification for new freq with or
without both {PRE|POST}CHANGE notifications for last freq. This is
useful at multiple places, especially for sending transition failure
notifications.
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Use common clock framework (CCF) APIs to set the clock rates
instead of direct register manipulation. This now updates the
sysfs entry (cpuinfo_cur_freq) correctly which did not reflect
the correct value until now. While at it clean up the PLL s-div
parameter setting as it is handled by the PLL driver.
Signed-off-by: Sachin Kamat <sachin.kamat@linaro.org>
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
Reviewed-by: Lukasz Majewski <l.majewski@samsung.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
When a CPU is hot removed we'll cancel all the delayed work items via
gov_cancel_work(). Sometimes the delayed work function determines that
it should adjust the delay for all other CPUs that the policy is
managing. If this scenario occurs, the canceling CPU will cancel its own
work but queue up the other CPUs works to run.
Commit 3617f2 (cpufreq: Fix timer/workqueue corruption due to double
queueing) has tried to fix this, but reading governor_enabled is not
protected by cpufreq_governor_lock. Even though od_dbs_timer() checks
governor_enabled before gov_queue_work(), this scenario may occur. For
example:
CPU0 CPU1
---- ----
cpu_down()
... <work runs>
__cpufreq_remove_dev() od_dbs_timer()
__cpufreq_governor() policy->governor_enabled
policy->governor_enabled = false;
cpufreq_governor_dbs()
case CPUFREQ_GOV_STOP:
gov_cancel_work(dbs_data, policy);
cpu0 work is canceled
timer is canceled
cpu1 work is canceled
<waits for cpu1>
gov_queue_work(*, *, true);
cpu0 work queued
cpu1 work queued
cpu2 work queued
...
cpu1 work is canceled
cpu2 work is canceled
...
At the end of the GOV_STOP case cpu0 still has a work queued to
run although the code is expecting all of the works to be
canceled. __cpufreq_remove_dev() will then proceed to
re-initialize all the other CPUs works except for the CPU that is
going down. The CPUFREQ_GOV_START case in cpufreq_governor_dbs()
will trample over the queued work and debugobjects will spit out
a warning:
WARNING: at lib/debugobjects.c:260 debug_print_object+0x94/0xbc()
ODEBUG: init active (active state 0) object type: timer_list hint: delayed_work_timer_fn+0x0/0x14
Modules linked in:
CPU: 1 PID: 1205 Comm: sh Tainted: G W 3.10.0 #200
[<c01144f0>] (unwind_backtrace+0x0/0xf8) from [<c0111d98>] (show_stack+0x10/0x14)
[<c0111d98>] (show_stack+0x10/0x14) from [<c01272cc>] (warn_slowpath_common+0x4c/0x68)
[<c01272cc>] (warn_slowpath_common+0x4c/0x68) from [<c012737c>] (warn_slowpath_fmt+0x30/0x40)
[<c012737c>] (warn_slowpath_fmt+0x30/0x40) from [<c034c640>] (debug_print_object+0x94/0xbc)
[<c034c640>] (debug_print_object+0x94/0xbc) from [<c034c7f8>] (__debug_object_init+0xc8/0x3c0)
[<c034c7f8>] (__debug_object_init+0xc8/0x3c0) from [<c01360e0>] (init_timer_key+0x20/0x104)
[<c01360e0>] (init_timer_key+0x20/0x104) from [<c04872ac>] (cpufreq_governor_dbs+0x1dc/0x68c)
[<c04872ac>] (cpufreq_governor_dbs+0x1dc/0x68c) from [<c04833a8>] (__cpufreq_governor+0x80/0x1b0)
[<c04833a8>] (__cpufreq_governor+0x80/0x1b0) from [<c0483704>] (__cpufreq_remove_dev.isra.12+0x22c/0x380)
[<c0483704>] (__cpufreq_remove_dev.isra.12+0x22c/0x380) from [<c0692f38>] (cpufreq_cpu_callback+0x48/0x5c)
[<c0692f38>] (cpufreq_cpu_callback+0x48/0x5c) from [<c014fb40>] (notifier_call_chain+0x44/0x84)
[<c014fb40>] (notifier_call_chain+0x44/0x84) from [<c012ae44>] (__cpu_notify+0x2c/0x48)
[<c012ae44>] (__cpu_notify+0x2c/0x48) from [<c068dd40>] (_cpu_down+0x80/0x258)
[<c068dd40>] (_cpu_down+0x80/0x258) from [<c068df40>] (cpu_down+0x28/0x3c)
[<c068df40>] (cpu_down+0x28/0x3c) from [<c068e4c0>] (store_online+0x30/0x74)
[<c068e4c0>] (store_online+0x30/0x74) from [<c03a7308>] (dev_attr_store+0x18/0x24)
[<c03a7308>] (dev_attr_store+0x18/0x24) from [<c0256fe0>] (sysfs_write_file+0x100/0x180)
[<c0256fe0>] (sysfs_write_file+0x100/0x180) from [<c01fec9c>] (vfs_write+0xbc/0x184)
[<c01fec9c>] (vfs_write+0xbc/0x184) from [<c01ff034>] (SyS_write+0x40/0x68)
[<c01ff034>] (SyS_write+0x40/0x68) from [<c010e200>] (ret_fast_syscall+0x0/0x48)
In gov_queue_work(), lock cpufreq_governor_lock before gov_queue_work,
and unlock it after __gov_queue_work(). In this way, governor_enabled
is guaranteed not changed in gov_queue_work().
Signed-off-by: Jane Li <jiel@marvell.com>
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
Reviewed-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Dirk Brandewie
Viresh Kumar
Paul Bolle
Rafael J. Wysocki
Mikulas Patocka
Ramkumar Ramachandra
Lukasz Majewski
John Tobias
Shawn Guo
Anson Huang
Sachin Kamat
Jane Li