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...
>
> 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?
--
~Vinod
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