[Intel-gfx] [PATCH] drm/i915: use the correct obj when preparing the sprite plane

[Paulo Zanoni]

From: Paulo Zanoni <paulo.r.zanoni at intel.com>

Commit "drm/i915: create a prepare phase for sprite plane updates"
changed the old_obj pointer we use when committing sprite planes,
which caused a WARN() and a BUG() to be triggered. This patch should
revert the code back to the previous behavior, fixing the regression.

Regression introduced by:
    commit ec82cb793c9224e0692eed904f43490cf70e8258
    Author: Gustavo Padovan <gustavo.padovan at collabora.co.uk>
    Date:   Fri Oct 24 14:51:32 2014 +0100
        drm/i915: create a prepare phase for sprite plane updates

Credits to Imre Deak for pointing out the exact lines that were wrong.

Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=85634
Testcase: igt/pm_rpm/legacy-planes
Testcase: igt/pm_rpm/legacy-planes-dpms
Testcase: igt/pm_rpm/universal-planes
Testcase: igt/pm_rpm/universal-planes-dpms
Credits-to: Imre Deak <imre.deak at intel.com>
Cc: Gustavo Padovan <gustavo.padovan at collabora.co.uk>
Cc: Ville Syrjälä <ville.syrjala at linux.intel.com>
Signed-off-by: Paulo Zanoni <paulo.r.zanoni at intel.com>
---
 drivers/gpu/drm/i915/intel_sprite.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/i915/intel_sprite.c b/drivers/gpu/drm/i915/intel_sprite.c
index 8b80d68..1c874309 100644
--- a/drivers/gpu/drm/i915/intel_sprite.c
+++ b/drivers/gpu/drm/i915/intel_sprite.c
@@ -1197,10 +1197,11 @@ intel_prepare_sprite_plane(struct drm_plane *plane,
 	struct drm_device *dev = plane->dev;
 	struct drm_crtc *crtc = state->crtc;
 	struct intel_crtc *intel_crtc = to_intel_crtc(crtc);
+	struct intel_plane *intel_plane = to_intel_plane(plane);
 	enum pipe pipe = intel_crtc->pipe;
 	struct drm_framebuffer *fb = state->fb;
 	struct drm_i915_gem_object *obj = intel_fb_obj(fb);
-	struct drm_i915_gem_object *old_obj = intel_fb_obj(plane->fb);
+	struct drm_i915_gem_object *old_obj = intel_plane->obj;
 	int ret;
 
 	if (old_obj != obj) {
-- 
2.1.1