overlay: Fill the blank charts with error messages

Instead of showing nothing, show a "space left intentionally blank"
message.

Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>

1 files changed, 1 insertions, 0 deletions

diff --git a/overlay/gpu-perf.h b/overlay/gpu-perf.h
index 3b91bd59..53699f75 100644
--- a/overlay/gpu-perf.h
+++ b/overlay/gpu-perf.h
@@ -30,6 +30,7 @@
 #define MAX_RINGS 4
 
 struct gpu_perf {
+	const char *error;
 	int page_size;
 	int nr_cpus;
 	int nr_events;