On Tue, 2013-03-05 at 14:56 +0530, Vinod Koul wrote:
> On Mon, Mar 04, 2013 at 11:09:30AM +0200, Andy Shevchenko wrote:
> > @@ -0,0 +1,48 @@
> > + DMA Test Guide
> > + ==============
> > +
> > + Andy Shevchenko <andriy.shevche...@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
> How do you terminate a test? Esp if you have started bunch of concurent tests
> and want to terminate one of them...
There is only one test in progress is possible.
To stop the test simple echo 0 > run (Probable that should be in
documentation as well)
> > static struct dmatest_info test_info;
> > @@ -718,7 +729,7 @@ static bool filter(struct dma_chan *chan, void *param)
> > return true;
> > }
> >
> > -static int run_threaded_test(struct dmatest_info *info)
> > +static int __run_threaded_test(struct dmatest_info *info)
> > {
> > dma_cap_mask_t mask;
> > struct dma_chan *chan;
> > @@ -744,7 +755,19 @@ static int run_threaded_test(struct dmatest_info *info)
> > return err;
> > }
> >
> > -static void stop_threaded_test(struct dmatest_info *info)
> > +#ifndef MODULE
> > +static int run_threaded_test(struct dmatest_info *info)
> > +{
> > + int ret;
> > +
> > + mutex_lock(&info->lock);
> > + ret = __run_threaded_test(info);
> > + mutex_unlock(&info->lock);
> > + return ret;
> > +}
> > +#endif
> > +
> > +static void __stop_threaded_test(struct dmatest_info *info)
> > {
> > struct dmatest_chan *dtc, *_dtc;
> > struct dma_chan *chan;
> > @@ -760,13 +783,234 @@ static void stop_threaded_test(struct dmatest_info
> > *info)
> > info->nr_channels = 0;
> > }
> >
> > +static void stop_threaded_test(struct dmatest_info *info)
> > +{
> > + mutex_lock(&info->lock);
> > + __stop_threaded_test(info);
> > + mutex_unlock(&info->lock);
> > +}
> > +
> > +static int __restart_threaded_test(struct dmatest_info *info, bool run)
> > +{
> > + struct dmatest_params *params = &info->params;
> > + int ret;
> > +
> > + /* Stop any running test first */
> > + __stop_threaded_test(info);
> > +
> > + if (run == false)
> > + return 0;
> > +
> > + /* Copy test parameters */
> > + memcpy(params, &info->dbgfs_params, sizeof(*params));
> what if the params are not yet filled by user... for module case?
Defaults are provided by constants in the top of file. They are copied
when module_init is called.
--
Andy Shevchenko <andriy.shevche...@linux.intel.com>
Intel Finland Oy
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