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Diffstat (limited to 'Documentation/dmaengine/dmatest.txt')
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diff --git a/Documentation/dmaengine/dmatest.txt b/Documentation/dmaengine/dmatest.txt deleted file mode 100644 index fb683c72dea8..000000000000 --- a/Documentation/dmaengine/dmatest.txt +++ /dev/null @@ -1,92 +0,0 @@ - DMA Test Guide - ============== - - Andy Shevchenko <andriy.shevchenko@linux.intel.com> - -This small document introduces how to test DMA drivers using dmatest module. - - Part 1 - How to build the test module - -The menuconfig contains an option that could be found by following path: - Device Drivers -> DMA Engine support -> DMA Test client - -In the configuration file the option called CONFIG_DMATEST. The dmatest could -be built as module or inside kernel. Let's consider those cases. - - Part 2 - When dmatest is built as a module... - -Example of usage: - % modprobe dmatest channel=dma0chan0 timeout=2000 iterations=1 run=1 - -...or: - % 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: - - 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 -emitted. After that only test failure messages are reported until the test -stops. - -Note that running a new test will not stop any in progress test. - -The following command returns the state of the test. - % cat /sys/module/dmatest/parameters/run - -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 -initialization to pause until a test run has completed, while reading -/sys/module/dmatest/parameters/wait waits for any running test to complete -before returning. For example, the following scripts wait for 42 tests -to complete before exiting. Note that if 'iterations' is set to 'infinite' then -waiting is disabled. - -Example: - % modprobe dmatest run=1 iterations=42 wait=1 - % modprobe -r dmatest -...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 -for the first performed test. After user gets a control, the test could be -re-run with the same or different parameters. For the details see the above -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 -case. You always could check them at run-time by running - % grep -H . /sys/module/dmatest/parameters/* - - Part 4 - Gathering the test results - -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>)" - -Example of output: - % 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 parens represents additional information, e.g. error code, error counter, -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. - -Example: - % 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 -above format. |