dmatest: add dma interrupts and callbacks

Use the callback infrastructure to report driver/hardware hangs or
missed interrupts.  Since this makes the test threads much more
aggressive (from: explicit 1ms sleep to: wait_for_completion) we set the
nice value to 10 so as to not swamp legitimate tasks.

Signed-off-by: Dan Williams <dan.j.williams@intel.com>

1 files changed, 27 insertions, 10 deletions

diff --git a/drivers/dma/dmatest.c b/drivers/dma/dmatest.c
index 224acf478fec..a27c0fb1bc11 100644
--- a/drivers/dma/dmatest.c
+++ b/drivers/dma/dmatest.c
@@ -196,6 +196,11 @@ static unsigned int dmatest_verify(u8 **bufs, unsigned int start,
         return error_count;
 }
 
+static void dmatest_callback(void *completion)
+{
+        complete(completion);
+}
+
 /*
  * This function repeatedly tests DMA transfers of various lengths and
  * offsets for a given operation type until it is told to exit by
@@ -261,13 +266,17 @@ static int dmatest_func(void *data)
         }
         thread->dsts[i] = NULL;
 
-        flags = DMA_CTRL_ACK | DMA_COMPL_SKIP_DEST_UNMAP;
+        set_user_nice(current, 10);
+
+        flags = DMA_CTRL_ACK | DMA_COMPL_SKIP_DEST_UNMAP | DMA_PREP_INTERRUPT;
 
         while (!kthread_should_stop()) {
                 struct dma_device *dev = chan->device;
                 struct dma_async_tx_descriptor *tx = NULL;
                 dma_addr_t dma_srcs[src_cnt];
                 dma_addr_t dma_dsts[dst_cnt];
+                struct completion cmp;
+                unsigned long tmo = msecs_to_jiffies(3000);
 
                 total_tests++;
 
@@ -318,7 +327,10 @@ static int dmatest_func(void *data)
                         failed_tests++;
                         continue;
                 }
-                tx->callback = NULL;
+
+                init_completion(&cmp);
+                tx->callback = dmatest_callback;
+                tx->callback_param = &cmp;
                 cookie = tx->tx_submit(tx);
 
                 if (dma_submit_error(cookie)) {
@@ -332,18 +344,23 @@ static int dmatest_func(void *data)
                 }
                 dma_async_issue_pending(chan);
 
-                do {
-                        msleep(1);
-                        status = dma_async_is_tx_complete(
-                                        chan, cookie, NULL, NULL);
-                } while (status == DMA_IN_PROGRESS);
+                tmo = wait_for_completion_timeout(&cmp, tmo);
+                status = dma_async_is_tx_complete(chan, cookie, NULL, NULL);
 
-                if (status == DMA_ERROR) {
-                        pr_warning("%s: #%u: error during copy\n",
-                                        thread_name, total_tests - 1);
+                if (tmo == 0) {
+                        pr_warning("%s: #%u: test timed out\n",
+                                   thread_name, total_tests - 1);
+                        failed_tests++;
+                        continue;
+                } else if (status != DMA_SUCCESS) {
+                        pr_warning("%s: #%u: got completion callback,"
+                                   " but status is \'%s\'\n",
+                                   thread_name, total_tests - 1,
+                                   status == DMA_ERROR ? "error" : "in progress");
                         failed_tests++;
                         continue;
                 }
+
                 /* Unmap by myself (see DMA_COMPL_SKIP_DEST_UNMAP above) */
                 for (i = 0; i < dst_cnt; i++)
                         dma_unmap_single(dev->dev, dma_dsts[i], test_buf_size,