This fixed some errors and warnings in cpu-idle-cooling.rst and client.rst.
Sphinx parallel build error:
docutils.utils.SystemMessage: ...Documentation/driver-api/thermal/cpu-idle-cooling.rst:96: (SEVERE/4) Unexpected section title.
Sphinx parallel build error:
docutils.utils.SystemMessage: ...Documentation/driver-api/dmaengine/client.rst:155: (SEVERE/4) Unexpected section title.
Signed-off-by: Changbin Du <changbin.du@xxxxxxxxx>
---
v2: rebase.
---
Documentation/driver-api/dmaengine/client.rst | 14 +++++++---
.../driver-api/thermal/cpu-idle-cooling.rst | 27 ++++++++++---------
Documentation/driver-api/thermal/index.rst | 1 +
3 files changed, 26 insertions(+), 16 deletions(-)
diff --git a/Documentation/driver-api/dmaengine/client.rst b/Documentation/driver-api/dmaengine/client.rst
index a9a7a3c84c63..2104830a99ae 100644
--- a/Documentation/driver-api/dmaengine/client.rst
+++ b/Documentation/driver-api/dmaengine/client.rst
@@ -151,8 +151,8 @@ The details of these operations are:
Note that callbacks will always be invoked from the DMA
engines tasklet, never from interrupt context.
- Optional: per descriptor metadata
- ---------------------------------
+ **Optional: per descriptor metadata**
+
DMAengine provides two ways for metadata support.
DESC_METADATA_CLIENT
@@ -199,12 +199,15 @@ The details of these operations are:
DESC_METADATA_CLIENT
- DMA_MEM_TO_DEV / DEV_MEM_TO_MEM:
+
1. prepare the descriptor (dmaengine_prep_*)
construct the metadata in the client's buffer
2. use dmaengine_desc_attach_metadata() to attach the buffer to the
descriptor
3. submit the transfer
+
- DMA_DEV_TO_MEM:
+
1. prepare the descriptor (dmaengine_prep_*)
2. use dmaengine_desc_attach_metadata() to attach the buffer to the
descriptor
@@ -215,6 +218,7 @@ The details of these operations are:
DESC_METADATA_ENGINE
- DMA_MEM_TO_DEV / DEV_MEM_TO_MEM:
+
1. prepare the descriptor (dmaengine_prep_*)
2. use dmaengine_desc_get_metadata_ptr() to get the pointer to the
engine's metadata area
@@ -222,7 +226,9 @@ The details of these operations are:
4. use dmaengine_desc_set_metadata_len() to tell the DMA engine the
amount of data the client has placed into the metadata buffer
5. submit the transfer
+
- DMA_DEV_TO_MEM:
+
1. prepare the descriptor (dmaengine_prep_*)
2. submit the transfer
3. on transfer completion, use dmaengine_desc_get_metadata_ptr() to get
@@ -278,8 +284,8 @@ The details of these operations are:
void dma_async_issue_pending(struct dma_chan *chan);
-Further APIs:
--------------
+Further APIs
+------------
1. Terminate APIs
diff --git a/Documentation/driver-api/thermal/cpu-idle-cooling.rst b/Documentation/driver-api/thermal/cpu-idle-cooling.rst
index 9f0016ee4cfb..698fcadbecee 100644
--- a/Documentation/driver-api/thermal/cpu-idle-cooling.rst
+++ b/Documentation/driver-api/thermal/cpu-idle-cooling.rst
@@ -1,6 +1,9 @@
+================
+CPU Idle Cooling
+================
-Situation:
-----------
+Situation
+---------
Under certain circumstances a SoC can reach a critical temperature
limit and is unable to stabilize the temperature around a temperature
@@ -24,8 +27,8 @@ with a power less than the requested power budget and the next OPP
exceeds the power budget. An intermediate OPP could have been used if
it were present.
-Solutions:
-----------
+Solutions
+---------
If we can remove the static and the dynamic leakage for a specific
duration in a controlled period, the SoC temperature will
@@ -45,12 +48,12 @@ idle state target residency, we lead to dropping the static and the
dynamic leakage for this period (modulo the energy needed to enter
this state). So the sustainable power with idle cycles has a linear
relation with the OPP’s sustainable power and can be computed with a
-coefficient similar to:
+coefficient similar to::
Power(IdleCycle) = Coef x Power(OPP)
-Idle Injection:
----------------
+Idle Injection
+--------------
The base concept of the idle injection is to force the CPU to go to an
idle state for a specified time each control cycle, it provides
@@ -136,7 +139,7 @@ Power considerations
--------------------
When we reach the thermal trip point, we have to sustain a specified
-power for a specific temperature but at this time we consume:
+power for a specific temperature but at this time we consume::
Power = Capacitance x Voltage^2 x Frequency x Utilisation
@@ -145,7 +148,7 @@ wrong in the system setup). The ‘Capacitance’ and ‘Utilisation’ are a
fixed value, ‘Voltage’ and the ‘Frequency’ are fixed artificially
because we don’t want to change the OPP. We can group the
‘Capacitance’ and the ‘Utilisation’ into a single term which is the
-‘Dynamic Power Coefficient (Cdyn)’ Simplifying the above, we have:
+‘Dynamic Power Coefficient (Cdyn)’ Simplifying the above, we have::
Pdyn = Cdyn x Voltage^2 x Frequency
@@ -154,7 +157,7 @@ in order to target the sustainable power defined in the device
tree. So with the idle injection mechanism, we want an average power
(Ptarget) resulting in an amount of time running at full power on a
specific OPP and idle another amount of time. That could be put in a
-equation:
+equation::
P(opp)target = ((Trunning x (P(opp)running) + (Tidle x P(opp)idle)) /
(Trunning + Tidle)
@@ -165,7 +168,7 @@ equation:
At this point if we know the running period for the CPU, that gives us
the idle injection we need. Alternatively if we have the idle
-injection duration, we can compute the running duration with:
+injection duration, we can compute the running duration with::
Trunning = Tidle / ((P(opp)running / P(opp)target) - 1)
@@ -188,7 +191,7 @@ However, in this demonstration we ignore three aspects:
target residency, otherwise we end up consuming more energy and
potentially invert the mitigation effect
-So the final equation is:
+So the final equation is::
Trunning = (Tidle - Twakeup ) x
(((P(opp)dyn + P(opp)static ) - P(opp)target) / P(opp)target )
diff --git a/Documentation/driver-api/thermal/index.rst b/Documentation/driver-api/thermal/index.rst
index 5ba61d19c6ae..4cb0b9b6bfb8 100644
--- a/Documentation/driver-api/thermal/index.rst
+++ b/Documentation/driver-api/thermal/index.rst
@@ -8,6 +8,7 @@ Thermal
:maxdepth: 1
cpu-cooling-api
+ cpu-idle-cooling
sysfs-api
power_allocator
--
2.24.0
