The milli-Watts precision causes rounding errors while calculating
efficiency cost for each OPP. This is especially visible in the 'simple'
Energy Model (EM), where the power for each OPP is provided from OPP
framework. This can cause some OPPs to be marked inefficient, while
using micro-Watts precision that might not happen.
Update all EM users which access 'power' field and assume the value is
in milli-Watts.
Solve also an issue with potential overflow in calculation of energy
estimation on 32bit machine. It's needed now since the power value
(thus the 'cost' as well) are higher.
Example calculation which shows the rounding error and impact:
power = 'dyn-power-coeff' * volt_mV * volt_mV * freq_MHz
power_a_uW = (100 * 600mW * 600mW * 500MHz) / 10^6 = 18000
power_a_mW = (100 * 600mW * 600mW * 500MHz) / 10^9 = 18
power_b_uW = (100 * 605mW * 605mW * 600MHz) / 10^6 = 21961
power_b_mW = (100 * 605mW * 605mW * 600MHz) / 10^9 = 21
max_freq = 2000MHz
cost_a_mW = 18 * 2000MHz/500MHz = 72
cost_a_uW = 18000 * 2000MHz/500MHz = 72000
cost_b_mW = 21 * 2000MHz/600MHz = 70 // <- artificially better
cost_b_uW = 21961 * 2000MHz/600MHz = 73203
The 'cost_b_mW' (which is based on old milli-Watts) is misleadingly
better that the 'cost_b_uW' (this patch uses micro-Watts) and such
would have impact on the 'inefficient OPPs' information in the Cpufreq
framework. This patch set removes the rounding issue.
Signed-off-by: Lukasz Luba <lukasz.luba@arm.com>
Acked-by: Daniel Lezcano <daniel.lezcano@linaro.org>
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
The .active_power() callback passes the device pointer when it's called.
Aligned with a convetion present in other subsystems and pass the 'dev'
as a first argument. It looks more cleaner.
Adjust all affected drivers which implement that API callback.
Suggested-by: Ionela Voinescu <ionela.voinescu@arm.com>
Signed-off-by: Lukasz Luba <lukasz.luba@arm.com>
Reviewed-by: Ionela Voinescu <ionela.voinescu@arm.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
When hotpluging policy cpu, cpu policy init will be called multiple times.
Unplug CPU7 -> CPU6 -> CPU5 -> CPU4, then plug CPU4 again.
In this case, devm_remap will double remap and resource allocate fail.
So replace devm_remap to ioremap and release resources in cpu policy exit.
Signed-off-by: Hector.Yuan <hector.yuan@mediatek.com>
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
The new cpufreq table flag RELATION_E introduced a new "efficient"
parameter for the cpufreq_table_find*() functions.
Fixes: 1f39fa0dcc (cpufreq: Introducing CPUFREQ_RELATION_E)
Signed-off-by: Vincent Donnefort <vincent.donnefort@arm.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Introduce cpufreq HW driver which can support
CPU frequency adjust in MT6779 platform.
Signed-off-by: Hector.Yuan <hector.yuan@mediatek.com>
[ Viresh: Massaged the patch and cleaned some stuff. ]
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Lukasz Luba