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Commit bcc567e3 authored by Andy Shevchenko's avatar Andy Shevchenko Committed by Vinod Koul
Browse files

dmatest: do not allow to interrupt ongoing tests 



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: default avatarAndy Shevchenko <andriy.shevchenko@linux.intel.com>
Reported-by: default avatarWill Deacon <will.deacon@arm.com>
Tested-by: default avatarWill Deacon <will.deacon@arm.com>
Signed-off-by: default avatarVinod Koul <vinod.koul@intel.com>
parent 9ecb41bd

Documentation/dmatest.txt

+3 −3
Original line number Diff line number Diff line
@@ -34,7 +34,7 @@ command: 
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.

Note that running a new test will not stop any in progress test.



The following command should return actual state of the test.

	% cat /sys/kernel/debug/dmatest/run
@@ -52,8 +52,8 @@ To wait for test done the user may perform a busy loop that checks the state. 


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 "Part 2 - When dmatest is built as a module..."

re-run with the same or different parameters. For the details see the above

section "Part 2 - 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

drivers/dma/dmatest.c

+23 −22
Original line number Diff line number Diff line
@@ -716,8 +716,7 @@ static int dmatest_func(void *data) 
		}

		dma_async_issue_pending(chan);



		wait_event_freezable_timeout(done_wait,

					     done.done || kthread_should_stop(),

		wait_event_freezable_timeout(done_wait, done.done,

					     msecs_to_jiffies(params->timeout));



		status = dma_async_is_tx_complete(chan, cookie, NULL, NULL);
@@ -997,7 +996,6 @@ static void stop_threaded_test(struct dmatest_info *info) 
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);
@@ -1012,13 +1010,23 @@ static int __restart_threaded_test(struct dmatest_info *info, bool run) 
	memcpy(params, &info->dbgfs_params, sizeof(*params));



	/* Run test with new parameters */

	ret = __run_threaded_test(info);

	if (ret) {

		__stop_threaded_test(info);

		pr_err("dmatest: Can't run test\n");

	return __run_threaded_test(info);

}



	return ret;

static bool __is_threaded_test_run(struct dmatest_info *info)

{

	struct dmatest_chan *dtc;



	list_for_each_entry(dtc, &info->channels, node) {

		struct dmatest_thread *thread;



		list_for_each_entry(thread, &dtc->threads, node) {

			if (!thread->done)

				return true;

		}

	}



	return false;

}



static ssize_t dtf_write_string(void *to, size_t available, loff_t *ppos,
@@ -1091,22 +1099,10 @@ static ssize_t dtf_read_run(struct file *file, char __user *user_buf, 
{

	struct dmatest_info *info = file->private_data;

	char buf[3];

	struct dmatest_chan *dtc;

	bool alive = false;



	mutex_lock(&info->lock);

	list_for_each_entry(dtc, &info->channels, node) {

		struct dmatest_thread *thread;



		list_for_each_entry(thread, &dtc->threads, node) {

			if (!thread->done) {

				alive = true;

				break;

			}

		}

	}



	if (alive) {

	if (__is_threaded_test_run(info)) {

		buf[0] = 'Y';

	} else {

		__stop_threaded_test(info);
@@ -1132,7 +1128,12 @@ static ssize_t dtf_write_run(struct file *file, const char __user *user_buf, 


	if (strtobool(buf, &bv) == 0) {

		mutex_lock(&info->lock);



		if (__is_threaded_test_run(info))

			ret = -EBUSY;

		else

			ret = __restart_threaded_test(info, bv);



		mutex_unlock(&info->lock);

	}