diff options
Diffstat (limited to 'Documentation')
| -rw-r--r-- | Documentation/dmatest.txt | 27 |
1 files changed, 13 insertions, 14 deletions
diff --git a/Documentation/dmatest.txt b/Documentation/dmatest.txt index 8b7a5c879df9..45b8c95f1a21 100644 --- a/Documentation/dmatest.txt +++ b/Documentation/dmatest.txt @@ -16,9 +16,8 @@ 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. There are two important files located. First -is the 'run' node that controls run and stop phases of the test, and the second -one, 'results', is used to get the test case results. +folder with a file named 'run' nodes will be created. 'run' controls run and +stop phases of the test. Note that in this case test will not run on load automatically. @@ -32,8 +31,9 @@ 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. +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. @@ -62,19 +62,18 @@ case. You always could check them at run-time by running Part 4 - Gathering the test results -The module provides a storage for the test results in the memory. The gathered -data could be used after test is done. +Test results are printed to the kernel log buffer with the format: -The special file 'results' in the debugfs represents gathered data of the in -progress test. The messages collected are printed to the kernel log as well. +"dmatest: result <channel>: <test id>: '<error msg>' with src_off=<val> dst_off=<val> len=<val> (<err code>)" Example of output: - % cat /sys/kernel/debug/dmatest/results - 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 parens represents additional information, e.g. error code, error counter, -or status. +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. -Note that the buffer comparison is done in the old way, i.e. data is not -collected and just printed out. +The details of a data miscompare error are also emitted, but do not follow the +above format. |
