Commit fb2d2329 authored by Geert Uytterhoeven's avatar Geert Uytterhoeven Committed by Rob Herring

dt-bindings: arm: idle-states: Use "e.g." and "i.e." consistently

Replace abbreviations "eg" and "ie" by "e.g." resp. "i.e." for
consistency.
Signed-off-by: default avatarGeert Uytterhoeven <geert+renesas@glider.be>
Reviewed-by: default avatarAmit Kucheria <amit.kucheria@linaro.org>
Acked-by: default avatarDaniel Lezcano <daniel.lezcano@linaro.org>
Signed-off-by: default avatarRob Herring <robh@kernel.org>
parent 08dc99e5
...@@ -28,7 +28,7 @@ PM implementation to put the processor in different idle states (which include ...@@ -28,7 +28,7 @@ PM implementation to put the processor in different idle states (which include
states listed above; "off" state is not an idle state since it does not have states listed above; "off" state is not an idle state since it does not have
wake-up capabilities, hence it is not considered in this document). wake-up capabilities, hence it is not considered in this document).
Idle state parameters (eg entry latency) are platform specific and need to be Idle state parameters (e.g. entry latency) are platform specific and need to be
characterized with bindings that provide the required information to OS PM characterized with bindings that provide the required information to OS PM
code so that it can build the required tables and use them at runtime. code so that it can build the required tables and use them at runtime.
...@@ -90,20 +90,20 @@ These timing parameters can be used by an OS in different circumstances. ...@@ -90,20 +90,20 @@ These timing parameters can be used by an OS in different circumstances.
An idle CPU requires the expected min-residency time to select the most An idle CPU requires the expected min-residency time to select the most
appropriate idle state based on the expected expiry time of the next IRQ appropriate idle state based on the expected expiry time of the next IRQ
(ie wake-up) that causes the CPU to return to the EXEC phase. (i.e. wake-up) that causes the CPU to return to the EXEC phase.
An operating system scheduler may need to compute the shortest wake-up delay An operating system scheduler may need to compute the shortest wake-up delay
for CPUs in the system by detecting how long will it take to get a CPU out for CPUs in the system by detecting how long will it take to get a CPU out
of an idle state, eg: of an idle state, e.g.:
wakeup-delay = exit-latency + max(entry-latency - (now - entry-timestamp), 0) wakeup-delay = exit-latency + max(entry-latency - (now - entry-timestamp), 0)
In other words, the scheduler can make its scheduling decision by selecting In other words, the scheduler can make its scheduling decision by selecting
(eg waking-up) the CPU with the shortest wake-up latency. (e.g. waking-up) the CPU with the shortest wake-up latency.
The wake-up latency must take into account the entry latency if that period The wake-up latency must take into account the entry latency if that period
has not expired. The abortable nature of the PREP period can be ignored has not expired. The abortable nature of the PREP period can be ignored
if it cannot be relied upon (e.g. the PREP deadline may occur much sooner than if it cannot be relied upon (e.g. the PREP deadline may occur much sooner than
the worst case since it depends on the CPU operating conditions, ie caches the worst case since it depends on the CPU operating conditions, i.e. caches
state). state).
An OS has to reliably probe the wakeup-latency since some devices can enforce An OS has to reliably probe the wakeup-latency since some devices can enforce
...@@ -183,15 +183,15 @@ and IDLE2: ...@@ -183,15 +183,15 @@ and IDLE2:
Graph 2: idle states min-residency example Graph 2: idle states min-residency example
In graph 2 above, that takes into account idle states entry/exit energy In graph 2 above, that takes into account idle states entry/exit energy
costs, it is clear that if the idle state residency time (ie time till next costs, it is clear that if the idle state residency time (i.e. time till next
wake-up IRQ) is less than IDLE2-min-residency, IDLE1 is the better idle state wake-up IRQ) is less than IDLE2-min-residency, IDLE1 is the better idle state
choice energywise. choice energywise.
This is mainly down to the fact that IDLE1 entry/exit energy costs are lower This is mainly down to the fact that IDLE1 entry/exit energy costs are lower
than IDLE2. than IDLE2.
However, the lower power consumption (ie shallower energy curve slope) of idle However, the lower power consumption (i.e. shallower energy curve slope) of
state IDLE2 implies that after a suitable time, IDLE2 becomes more energy idle state IDLE2 implies that after a suitable time, IDLE2 becomes more energy
efficient. efficient.
The time at which IDLE2 becomes more energy efficient than IDLE1 (and other The time at which IDLE2 becomes more energy efficient than IDLE1 (and other
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