Re: [PATCH 06/10] dmatest: run test via debugfs

[Vinod Koul <vinod.koul@intel.com>]

On Mon, Mar 04, 2013 at 11:09:30AM +0200, Andy Shevchenko wrote:
> @@ -0,0 +1,48 @@
> +				DMA Test Guide
> +				==============
> +
> +		Andy Shevchenko <andriy.shevchenko@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