patches.baytrail/1007-drm-no-op-out-GET_STATS-ioctl.patch

From d4f1e8ab1a773e1b6e4cf0841a1fa671c8b3b60c Mon Sep 17 00:00:00 2001
From: Daniel Vetter <daniel.vetter@ffwll.ch>
Date: Thu, 8 Aug 2013 15:41:32 +0200
Subject: drm: no-op out GET_STATS ioctl

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@anholt.net>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Reviewed-by: Eric Anholt <eric@anholt.net>
Signed-off-by: Dave Airlie <airlied@redhat.com>
(cherry picked from commit d79cdc8312689b39c6d83718c1c196af4b3cd18c)
Signed-off-by: Darren Hart <dvhart@linux.intel.com>
---
 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 e77bd8b57df2..49fd720b0c17 100644
--- a/drivers/gpu/drm/drm_ioctl.c
+++ b/drivers/gpu/drm/drm_ioctl.c
@@ -243,21 +243,10 @@ 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;
 }
 
-- 
1.8.5.rc3