[PATCH 07/10] dmatest: return actual state in 'run' file

From: Andy Shevchenko
Date: Mon Mar 04 2013 - 04:13:55 EST


The following command should return actual state of the test.
% cat /sys/kernel/debug/dmatest/run

To wait for test done the user may perform a busy loop that checks the state.
% while [ $(cat /sys/kernel/debug/dmatest/run) = "Y" ]
> do
> echo -n "."
> sleep 1
> done
> echo

Signed-off-by: Andy Shevchenko <andriy.shevchenko@xxxxxxxxxxxxxxx>
---
Documentation/dmatest.txt | 12 ++++++++++++
drivers/dma/dmatest.c | 23 +++++++++++++++++++++--
2 files changed, 33 insertions(+), 2 deletions(-)

diff --git a/Documentation/dmatest.txt b/Documentation/dmatest.txt
index 9a90729..3e17b55 100644
--- a/Documentation/dmatest.txt
+++ b/Documentation/dmatest.txt
@@ -36,6 +36,18 @@ in the original code.

Note that running a new test will stop any in progress test.

+The following command should return actual state of the test.
+ % cat /sys/kernel/debug/dmatest/run
+
+To wait for test done the user may perform a busy loop that checks the state.
+
+ % while [ $(cat /sys/kernel/debug/dmatest/run) = "Y" ]
+ > do
+ > echo -n "."
+ > sleep 1
+ > done
+ > echo
+
Part 3 - When built-in in the kernel...

The module parameters that is supplied to the kernel command line will be used
diff --git a/drivers/dma/dmatest.c b/drivers/dma/dmatest.c
index fc31542..d19234b 100644
--- a/drivers/dma/dmatest.c
+++ b/drivers/dma/dmatest.c
@@ -93,6 +93,7 @@ struct dmatest_thread {
u8 **srcs;
u8 **dsts;
enum dma_transaction_type type;
+ bool done;
};

struct dmatest_chan {
@@ -603,6 +604,8 @@ err_thread_type:
if (ret)
dmaengine_terminate_all(chan);

+ thread->done = true;
+
if (params->iterations > 0)
while (!kthread_should_stop()) {
DECLARE_WAIT_QUEUE_HEAD_ONSTACK(wait_dmatest_exit);
@@ -884,12 +887,28 @@ 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);
- if (info->nr_channels)
+ 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) {
buf[0] = 'Y';
- else
+ } else {
+ __stop_threaded_test(info);
buf[0] = 'N';
+ }
+
mutex_unlock(&info->lock);
buf[1] = '\n';
buf[2] = 0x00;
--
1.8.2.rc0.22.gb3600c3

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