1 files changed, 19 insertions, 7 deletions

diff --git a/drivers/gpu/nvgpu/gk20a/fecs_trace_gk20a.c b/drivers/gpu/nvgpu/gk20a/fecs_trace_gk20a.c
index 6b77dff5..1f86fd8f 100644
--- a/drivers/gpu/nvgpu/gk20a/fecs_trace_gk20a.c
+++ b/drivers/gpu/nvgpu/gk20a/fecs_trace_gk20a.c
@@ -720,15 +720,27 @@ static int gk20a_fecs_trace_enable(struct gk20a *g)
 {
         struct gk20a_fecs_trace *trace = g->fecs_trace;
         struct task_struct *task;
+        int write;
 
-        if (!trace->poll_task) {
-                task = kthread_run(gk20a_fecs_trace_periodic_polling, g, __func__);
-                if (unlikely(IS_ERR(task))) {
-                        gk20a_warn(dev_from_gk20a(g), "failed to create FECS polling task");
-                        return PTR_ERR(task);
-                }
-                trace->poll_task = task;
+        if (!trace)
+                return -EINVAL;
+
+        if  (trace->poll_task)
+                return 0;
+
+        /* drop data in hw buffer */
+        if (g->ops.fecs_trace.flush)
+                g->ops.fecs_trace.flush(g);
+        write = gk20a_fecs_trace_get_write_index(g);
+        gk20a_fecs_trace_set_read_index(g, write);
+
+        task = kthread_run(gk20a_fecs_trace_periodic_polling, g, __func__);
+        if (unlikely(IS_ERR(task))) {
+                gk20a_warn(dev_from_gk20a(g),
+                                "failed to create FECS polling task");
+                return PTR_ERR(task);
         }
+        trace->poll_task = task;
 
         return 0;
 }