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authorAndy Shevchenko <andriy.shevchenko@linux.intel.com>2013-03-04 11:09:30 +0200
committerVinod Koul <vinod.koul@intel.com>2013-04-15 09:51:17 +0530
commit851b7e16a07dfda6178d4e35fea9a9e3eb8954ae (patch)
tree7970966aa65fd72062a8944591c81993b1b7b932 /Documentation/dmatest.txt
parent15b8a8ea1a87313f1b46ea878c65942fd52147ed (diff)
dmatest: run test via debugfs
Instead of doing modprobe dmatest ... modprobe -r dmatest we allow user to run tests interactively. The dmatest could be built as module or inside kernel. Let's consider those cases. 1. When dmatest is built as a module... After mounting debugfs and loading the module, the /sys/kernel/debug/dmatest folder with nodes will be created. They are the same as module parameters with addition of the 'run' node that controls run and stop phases of the test. Note that in this case test will not run on load automatically. Example of usage: % echo dma0chan0 > /sys/kernel/debug/dmatest/channel % echo 2000 > /sys/kernel/debug/dmatest/timeout % echo 1 > /sys/kernel/debug/dmatest/iterations % echo 1 > /sys/kernel/debug/dmatest/run After a while you will start to get messages about current status or error like in the original code. Note that running a new test will stop any in progress test. 2. 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 interrupted or re-run with same or different parameters. For the details see the above section "1. When dmatest is built as a module..." In both cases the module parameters are used as initial values for the test case. You always could check them at run-time by running % grep -H . /sys/module/dmatest/parameters/* Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Signed-off-by: Vinod Koul <vinod.koul@intel.com>
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+ 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...
+
+After mounting debugfs and loading the module, the /sys/kernel/debug/dmatest
+folder with nodes will be created. They are the same as module parameters with
+addition of the 'run' node that controls run and stop phases of the test.
+
+Note that in this case test will not run on load automatically.
+
+Example of usage:
+ % echo dma0chan0 > /sys/kernel/debug/dmatest/channel
+ % echo 2000 > /sys/kernel/debug/dmatest/timeout
+ % echo 1 > /sys/kernel/debug/dmatest/iterations
+ % echo 1 > /sys/kernel/debug/dmatest/run
+
+Hint: available channel list could be extracted by running the following
+command:
+ % ls -1 /sys/class/dma/
+
+After a while you will start to get messages about current status or error like
+in the original code.
+
+Note that running a new test will stop any in progress test.
+
+ 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
+interrupted or re-run with 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 initial values for the test case.
+You always could check them at run-time by running
+ % grep -H . /sys/module/dmatest/parameters/*

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