Commit 179a214e authored by Vinod Koul's avatar Vinod Koul Committed by Jonathan Corbet

dmaengine: doc: ReSTize dmatest doc

This converts and moves dmatest file with some format
changes for RST style
Signed-off-by: default avatarVinod Koul <vinod.koul@intel.com>
Signed-off-by: default avatarJonathan Corbet <corbet@lwn.net>
parent eeb1c643
DMA Test Guide ==============
============== DMA Test Guide
==============
Andy Shevchenko <andriy.shevchenko@linux.intel.com> Andy Shevchenko <andriy.shevchenko@linux.intel.com>
This small document introduces how to test DMA drivers using dmatest module. This small document introduces how to test DMA drivers using dmatest module.
Part 1 - How to build the test module Part 1 - How to build the test module
=====================================
The menuconfig contains an option that could be found by following path: The menuconfig contains an option that could be found by following path:
Device Drivers -> DMA Engine support -> DMA Test client Device Drivers -> DMA Engine support -> DMA Test client
...@@ -13,25 +15,31 @@ The menuconfig contains an option that could be found by following path: ...@@ -13,25 +15,31 @@ The menuconfig contains an option that could be found by following path:
In the configuration file the option called CONFIG_DMATEST. The dmatest could In the configuration file the option called CONFIG_DMATEST. The dmatest could
be built as module or inside kernel. Let's consider those cases. be built as module or inside kernel. Let's consider those cases.
Part 2 - When dmatest is built as a module... Part 2 - When dmatest is built as a module
==========================================
Example of usage: Example of usage: ::
% modprobe dmatest channel=dma0chan0 timeout=2000 iterations=1 run=1
...or: % modprobe dmatest channel=dma0chan0 timeout=2000 iterations=1 run=1
% modprobe dmatest
% echo dma0chan0 > /sys/module/dmatest/parameters/channel
% echo 2000 > /sys/module/dmatest/parameters/timeout
% echo 1 > /sys/module/dmatest/parameters/iterations
% echo 1 > /sys/module/dmatest/parameters/run
...or on the kernel command line: ...or: ::
dmatest.channel=dma0chan0 dmatest.timeout=2000 dmatest.iterations=1 dmatest.run=1 % modprobe dmatest
% echo dma0chan0 > /sys/module/dmatest/parameters/channel
% echo 2000 > /sys/module/dmatest/parameters/timeout
% echo 1 > /sys/module/dmatest/parameters/iterations
% echo 1 > /sys/module/dmatest/parameters/run
Hint: available channel list could be extracted by running the following ...or on the kernel command line: ::
command:
% ls -1 /sys/class/dma/ dmatest.channel=dma0chan0 dmatest.timeout=2000 dmatest.iterations=1 dmatest.run=1
..hint:: available channel list could be extracted by running the following
command:
::
% ls -1 /sys/class/dma/
Once started a message like "dmatest: Started 1 threads using dma0chan0" is Once started a message like "dmatest: Started 1 threads using dma0chan0" is
emitted. After that only test failure messages are reported until the test emitted. After that only test failure messages are reported until the test
...@@ -39,8 +47,9 @@ stops. ...@@ -39,8 +47,9 @@ stops.
Note that running a new test will not stop any in progress test. Note that running a new test will not stop any in progress test.
The following command returns the state of the test. The following command returns the state of the test. ::
% cat /sys/module/dmatest/parameters/run
% cat /sys/module/dmatest/parameters/run
To wait for test completion userpace can poll 'run' until it is false, or use To wait for test completion userpace can poll 'run' until it is false, or use
the wait parameter. Specifying 'wait=1' when loading the module causes module the wait parameter. Specifying 'wait=1' when loading the module causes module
...@@ -50,15 +59,19 @@ before returning. For example, the following scripts wait for 42 tests ...@@ -50,15 +59,19 @@ before returning. For example, the following scripts wait for 42 tests
to complete before exiting. Note that if 'iterations' is set to 'infinite' then to complete before exiting. Note that if 'iterations' is set to 'infinite' then
waiting is disabled. waiting is disabled.
Example: Example: ::
% modprobe dmatest run=1 iterations=42 wait=1
% modprobe -r dmatest % modprobe dmatest run=1 iterations=42 wait=1
...or: % modprobe -r dmatest
% modprobe dmatest run=1 iterations=42
% cat /sys/module/dmatest/parameters/wait
% modprobe -r dmatest
Part 3 - When built-in in the kernel... ...or: ::
% modprobe dmatest run=1 iterations=42
% cat /sys/module/dmatest/parameters/wait
% modprobe -r dmatest
Part 3 - When built-in in the kernel
====================================
The module parameters that is supplied to the kernel command line will be used The module parameters that is supplied to the kernel command line will be used
for the first performed test. After user gets a control, the test could be for the first performed test. After user gets a control, the test could be
...@@ -66,27 +79,32 @@ re-run with the same or different parameters. For the details see the above ...@@ -66,27 +79,32 @@ re-run with the same or different parameters. For the details see the above
section "Part 2 - When dmatest is built as a module..." section "Part 2 - When dmatest is built as a module..."
In both cases the module parameters are used as the actual values for the test In both cases the module parameters are used as the actual values for the test
case. You always could check them at run-time by running case. You always could check them at run-time by running ::
% grep -H . /sys/module/dmatest/parameters/*
% grep -H . /sys/module/dmatest/parameters/*
Part 4 - Gathering the test results Part 4 - Gathering the test results
===================================
Test results are printed to the kernel log buffer with the format: Test results are printed to the kernel log buffer with the format: ::
"dmatest: result <channel>: <test id>: '<error msg>' with src_off=<val> dst_off=<val> len=<val> (<err code>)" "dmatest: result <channel>: <test id>: '<error msg>' with src_off=<val> dst_off=<val> len=<val> (<err code>)"
Example of output: Example of output: ::
% dmesg | tail -n 1
dmatest: result dma0chan0-copy0: #1: No errors with src_off=0x7bf dst_off=0x8ad len=0x3fea (0)
% dmesg | tail -n 1
dmatest: result dma0chan0-copy0: #1: No errors with src_off=0x7bf dst_off=0x8ad len=0x3fea (0)
The message format is unified across the different types of errors. A number in The message format is unified across the different types of errors. A number in
the parens represents additional information, e.g. error code, error counter, the parens represents additional information, e.g. error code, error counter,
or status. A test thread also emits a summary line at completion listing the or status. A test thread also emits a summary line at completion listing the
number of tests executed, number that failed, and a result code. number of tests executed, number that failed, and a result code.
Example: Example: ::
% dmesg | tail -n 1
dmatest: dma0chan0-copy0: summary 1 test, 0 failures 1000 iops 100000 KB/s (0) % dmesg | tail -n 1
dmatest: dma0chan0-copy0: summary 1 test, 0 failures 1000 iops 100000 KB/s (0)
The details of a data miscompare error are also emitted, but do not follow the The details of a data miscompare error are also emitted, but do not follow the
above format. above format.
...@@ -27,6 +27,16 @@ API of the DMAEngine. This is applicable only for slave DMA usage only. ...@@ -27,6 +27,16 @@ API of the DMAEngine. This is applicable only for slave DMA usage only.
client client
DMA Test documentation
----------------------
This book introduces how to test DMA drivers using dmatest module.
.. toctree::
:maxdepth: 1
dmatest
.. only:: subproject .. only:: subproject
Indices Indices
......
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