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authorAndy Shevchenko <andriy.shevchenko@linux.intel.com>2013-05-23 14:29:53 +0300
committerVinod Koul <vinod.koul@intel.com>2013-06-08 02:13:44 +0530
commitbcc567e3115055a9cc256183d72864f01286be22 (patch)
tree2775e4359ff7d53e8656c07954683135d2e15e0c
parent9ecb41bd8cf002fd8f3e063db4df81647ddd623c (diff)
downloadlinux-bcc567e3115055a9cc256183d72864f01286be22.tar.gz
linux-bcc567e3115055a9cc256183d72864f01286be22.tar.xz
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: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Reported-by: Will Deacon <will.deacon@arm.com> Tested-by: Will Deacon <will.deacon@arm.com> Signed-off-by: Vinod Koul <vinod.koul@intel.com>
-rw-r--r--Documentation/dmatest.txt6
-rw-r--r--drivers/dma/dmatest.c45
2 files changed, 26 insertions, 25 deletions
diff --git a/Documentation/dmatest.txt b/Documentation/dmatest.txt
index 279ac0a..132a094 100644
--- a/Documentation/dmatest.txt
+++ b/Documentation/dmatest.txt
@@ -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
diff --git a/drivers/dma/dmatest.c b/drivers/dma/dmatest.c
index d8ce4ec..e88ded2 100644
--- a/drivers/dma/dmatest.c
+++ b/drivers/dma/dmatest.c
@@ -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);
+}
+
+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 ret;
+ 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);
- ret = __restart_threaded_test(info, bv);
+
+ if (__is_threaded_test_run(info))
+ ret = -EBUSY;
+ else
+ ret = __restart_threaded_test(info, bv);
+
mutex_unlock(&info->lock);
}