[PATCH 37/39] drm: no-op out GET_STATS ioctl

[Daniel Vetter]

Again only used by a tests in libdrm and by dristat. Nowadays we have
much better tracing tools to get detailed insights into what a drm
driver is doing. And for a simple "does it work" kind of question that
these stats could answer we have plenty of dmesg debug log spew.

So I don't see any use for this stat gathering complexity at all.

To be able to gradually drop things start with ripping out the
interfaces to it, here the ioctl.

To prevent dristat from eating its own stack garbage we can't use the
drm_noop ioctl though, since we need to clear the return data with a
memset.

Cc: Eric Anholt <eric at anholt.net>
Signed-off-by: Daniel Vetter <daniel.vetter at ffwll.ch>
---
 drivers/gpu/drm/drm_ioctl.c | 13 +------------
 1 file changed, 1 insertion(+), 12 deletions(-)

diff --git a/drivers/gpu/drm/drm_ioctl.c b/drivers/gpu/drm/drm_ioctl.c
index 5159fa0..fbe9219 100644
--- a/drivers/gpu/drm/drm_ioctl.c
+++ b/drivers/gpu/drm/drm_ioctl.c
@@ -237,21 +237,10 @@ int drm_getstats(struct drm_device *dev, void *data,
 		 struct drm_file *file_priv)
 {
 	struct drm_stats *stats = data;
-	int i;
 
+	/* Clear stats to prevent userspace from eating its stack garbage. */
 	memset(stats, 0, sizeof(*stats));
 
-	for (i = 0; i < dev->counters; i++) {
-		if (dev->types[i] == _DRM_STAT_LOCK)
-			stats->data[i].value =
-			    (file_priv->master->lock.hw_lock ? file_priv->master->lock.hw_lock->lock : 0);
-		else
-			stats->data[i].value = atomic_read(&dev->counts[i]);
-		stats->data[i].type = dev->types[i];
-	}
-
-	stats->count = dev->counters;
-
 	return 0;
 }
 
-- 
1.8.3.2