Merge branch 'timers-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel...

[firefly-linux-kernel-4.4.55.git] / Documentation / dmatest.txt

diff --git a/Documentation/dmatest.txt b/Documentation/dmatest.txt
index 3e17b55a8ba3f697aa1f23ad863d02c69033bcde..132a094c7bc3790631b664efb20b6cfb21a3d42e 100644 (file)
--- a/Documentation/dmatest.txt
+++ b/Documentation/dmatest.txt
@@ -34,7 +34,7 @@ command:
 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.
+Note that running a new test will not stop any in progress test.
 
 The following command should return actual state of the test.
        % cat /sys/kernel/debug/dmatest/run
@@ -52,9 +52,30 @@ To wait for test done the user may perform a busy loop that checks the state.
 
 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..."
+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 initial 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
+
+The module provides a storage for the test results in the memory. The gathered
+data could be used after test is done.
+
+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.
+
+Example of output:
+       % cat /sys/kernel/debug/dmatest/results
+       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.
+
+Comparison between buffers is stored to the dedicated structure.
+
+Note that the verify result is now accessible only via file 'results' in the
+debugfs.