Commit ce65d55f authored by Vladimir Murzin's avatar Vladimir Murzin Committed by Vinod Koul
Browse files

dmaengine: dmatest: Prevent to run on misconfigured channel 



Andy reported that commit 6b41030f ("dmaengine: dmatest:
Restore default for channel") broke his scripts for the case
where "busy" channel is used for configuration with expectation
that run command would do nothing. Instead, behavior was
(unintentionally) changed to treat such case as under-configuration
and progress with defaults, i.e. run command would start a test
with default setting for channel (which would use all channels).

Restore original behavior with tracking status of channel setter
so we can distinguish between misconfigured and under-configured
cases in run command and act accordingly.

Fixes: 6b41030f ("dmaengine: dmatest: Restore default for channel")
Reported-by: default avatarAndy Shevchenko <andriy.shevchenko@linux.intel.com>
Tested-by: default avatarAndy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: default avatarVladimir Murzin <vladimir.murzin@arm.com>
Tested-by: default avatarPeter Ujfalusi <peter.ujfalusi@ti.com>
Signed-off-by: default avatarAndy Shevchenko <andriy.shevchenko@linux.intel.com>
Link: https://lore.kernel.org/r/20200922115847.30100-1-andriy.shevchenko@linux.intel.com


Signed-off-by: default avatarVinod Koul <vkoul@kernel.org>
parent f4d51dff

drivers/dma/dmatest.c

+21 −5
Original line number Diff line number Diff line
@@ -129,6 +129,7 @@ struct dmatest_params { 
 * @nr_channels:	number of channels under test

 * @lock:		access protection to the fields of this structure

 * @did_init:		module has been initialized completely

 * @last_error:		test has faced configuration issues

 */

static struct dmatest_info {

	/* Test parameters */
@@ -137,6 +138,7 @@ static struct dmatest_info { 
	/* Internal state */

	struct list_head	channels;

	unsigned int		nr_channels;

	int			last_error;

	struct mutex		lock;

	bool			did_init;

} test_info = {
@@ -1184,11 +1186,23 @@ static int dmatest_run_set(const char *val, const struct kernel_param *kp) 
		return ret;

	} else if (dmatest_run) {

		if (!is_threaded_test_pending(info)) {

			/*

			 * We have nothing to run. This can be due to:

			 */

			ret = info->last_error;

			if (ret) {

				/* 1) Misconfiguration */

				pr_err("Channel misconfigured, can't continue\n");

				mutex_unlock(&info->lock);

				return ret;

			} else {

				/* 2) We rely on defaults */

				pr_info("No channels configured, continue with any\n");

				if (!is_threaded_test_run(info))

					stop_threaded_test(info);

				add_threaded_test(info);

			}

		}

		start_threaded_tests(info);

	} else {

		stop_threaded_test(info);
@@ -1204,7 +1218,7 @@ static int dmatest_chan_set(const char *val, const struct kernel_param *kp) 
	struct dmatest_info *info = &test_info;

	struct dmatest_chan *dtc;

	char chan_reset_val[20];

	int ret = 0;

	int ret;



	mutex_lock(&info->lock);

	ret = param_set_copystring(val, kp);
@@ -1259,12 +1273,14 @@ static int dmatest_chan_set(const char *val, const struct kernel_param *kp) 
		goto add_chan_err;

	}



	info->last_error = ret;

	mutex_unlock(&info->lock);



	return ret;



add_chan_err:

	param_set_copystring(chan_reset_val, kp);

	info->last_error = ret;

	mutex_unlock(&info->lock);



	return ret;

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