[PATCH 4/4] drm: fix fb refcount issue with atomic modesetting

[Tomi Valkeinen]

After commit 027b3f8ba9277410c3191d72d1ed2c6146d8a668 ("drm/modes: stop
handling framebuffer special") extra fb refs are left around when doing
atomic modesetting.

The problem is that the new drm_property_change_valid_get() does not
return anything in the '**ref' parameter, which causes
'drm_property_change_valid_put' never to be called.

For some reason this doesn't cause problems with legacy API.

Also, previously the code only set the 'ref' variable for fbs, with this
patch the 'ref' is set for all objects.

So this is a bit of an RFC, as I don't understand all what's going on
here.

Signed-off-by: Tomi Valkeinen <tomi.valkeinen at ti.com>
---
 drivers/gpu/drm/drm_crtc.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/drm_crtc.c b/drivers/gpu/drm/drm_crtc.c
index 06b6e2173697..0e3cc66aa8b7 100644
--- a/drivers/gpu/drm/drm_crtc.c
+++ b/drivers/gpu/drm/drm_crtc.c
@@ -4839,7 +4839,8 @@ bool drm_property_change_valid_get(struct drm_property *property,
 		if (value == 0)
 			return true;
 
-		return _object_find(property->dev, value, property->values[0]) != NULL;
+		*ref = _object_find(property->dev, value, property->values[0]);
+		return *ref != NULL;
 	}
 
 	for (i = 0; i < property->num_values; i++)
-- 
2.5.0