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Diffstat (limited to 'Documentation/driver-api/dmaengine/dmatest.rst')
| -rw-r--r-- | Documentation/driver-api/dmaengine/dmatest.rst | 40 |
1 files changed, 22 insertions, 18 deletions
diff --git a/Documentation/driver-api/dmaengine/dmatest.rst b/Documentation/driver-api/dmaengine/dmatest.rst index 3922c0a3f0c0..7ce5e71c353e 100644 --- a/Documentation/driver-api/dmaengine/dmatest.rst +++ b/Documentation/driver-api/dmaengine/dmatest.rst @@ -6,10 +6,16 @@ Andy Shevchenko <andriy.shevchenko@linux.intel.com> This small document introduces how to test DMA drivers using dmatest module. +.. note:: + The test suite works only on the channels that have at least one + capability of the following: DMA_MEMCPY (memory-to-memory), DMA_MEMSET + (const-to-memory or memory-to-memory, when emulated), DMA_XOR, DMA_PQ. + 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 @@ -18,11 +24,11 @@ be built as module or inside kernel. Let's consider those cases. 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: :: +...or:: % modprobe dmatest % echo dma0chan0 > /sys/module/dmatest/parameters/channel @@ -30,14 +36,12 @@ Example of usage: :: % echo 1 > /sys/module/dmatest/parameters/iterations % echo 1 > /sys/module/dmatest/parameters/run -...or on the kernel command line: :: +...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: - -:: +.. hint:: + available channel list could be extracted by running the following command:: % ls -1 /sys/class/dma/ @@ -59,12 +63,12 @@ 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: :: +Example:: % modprobe dmatest run=1 iterations=42 wait=1 % modprobe -r dmatest -...or: :: +...or:: % modprobe dmatest run=1 iterations=42 % cat /sys/module/dmatest/parameters/wait @@ -76,7 +80,7 @@ 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..." +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 :: @@ -86,22 +90,22 @@ case. You always could check them at run-time by running :: 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>)" -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) -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. +The message format is unified across the different types of errors. A +number in the parentheses 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: :: +Example:: % dmesg | tail -n 1 dmatest: dma0chan0-copy0: summary 1 test, 0 failures 1000 iops 100000 KB/s (0) |