linux-toradex.git/drivers/dma/dmatest.c, branch v3.10.76

dmatest: do not allow to interrupt ongoing tests

2013-06-07T20:43:44+00:00

When user interrupts ongoing transfers the dmatest may end up with console
lockup, oops, or data mismatch. This patch prevents user to abort any ongoing
test.

Documentation is updated accordingly.

Signed-off-by: Andy Shevchenko 
Reported-by: Will Deacon 
Tested-by: Will Deacon 
Signed-off-by: Vinod Koul

dmatest: append verify result to results

2013-04-15T04:21:18+00:00

Comparison between buffers is stored to the dedicated structure.

Note that the verify result is now accessible only via file 'results' in the
debugfs.

Signed-off-by: Andy Shevchenko 
Signed-off-by: Vinod Koul

dmatest: gather test results in the linked list

2013-04-15T04:21:17+00:00

The patch provides a storage for the test results in the linked list. The
gathered data could be used after test is done.

The new file 'results' 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.

Note that the buffer comparison is done in the old way, i.e. data is not
collected and just printed out.

Signed-off-by: Andy Shevchenko 
Signed-off-by: Vinod Koul

dmatest: define MAX_ERROR_COUNT constant

2013-04-15T04:21:17+00:00

Its meaning is to limit amount of error messages to be printed out when buffer
mismatch is occured.

Signed-off-by: Andy Shevchenko 
Signed-off-by: Vinod Koul

dmatest: return actual state in 'run' file

2013-04-15T04:21:17+00:00

The following command should return actual state of the test.
	% cat /sys/kernel/debug/dmatest/run

To wait for test done the user may perform a busy loop that checks the state.
	% while [ $(cat /sys/kernel/debug/dmatest/run) = "Y" ]
	> do
	> 	echo -n "."
	> 	sleep 1
	> done
	> echo

Signed-off-by: Andy Shevchenko 
Signed-off-by: Vinod Koul

dmatest: run test via debugfs

2013-04-15T04:21:17+00:00

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 
Signed-off-by: Vinod Koul

dmatest: split test parameters to separate structure

2013-04-15T04:21:17+00:00

Better to keep test parameters separate from internal variables.

Signed-off-by: Andy Shevchenko 
Acked-by: Viresh Kumar 
Signed-off-by: Vinod Koul

dmatest: move dmatest_channels and nr_channels to dmatest_info

2013-04-15T04:21:17+00:00

We don't need to have them global and later we would like to protect access to
them as well.

Signed-off-by: Andy Shevchenko 
Acked-by: Viresh Kumar 
Signed-off-by: Vinod Koul

dmatest: create dmatest_info to keep test parameters

2013-04-15T04:21:17+00:00

The proposed change will remove usage of the module parameters as global
variables. In future it helps to run different test cases sequentially.

The patch introduces the run_threaded_test() and stop_threaded_test() functions
that could be used later outside of dmatest_init, dmatest_exit scope.

Signed-off-by: Andy Shevchenko 
Acked-by: Viresh Kumar 
Signed-off-by: Vinod Koul

dmatest: allocate memory for pq_coefs from heap

2013-04-15T04:21:16+00:00

This will help in future to hide a global variable usage.

Signed-off-by: Andy Shevchenko 
Acked-by: Viresh Kumar 
Signed-off-by: Vinod Koul