drm/imx: ipuv3-plane: Switch EBA buffer only when we don't need modeset

We added active plane reconfiguration support by forcing a full modeset
operation.  So, looking at old_plane_state->fb to determine whether we need to
switch EBA buffer(for hardware double buffering) in ipu_plane_atomic_set_base()
or not is no more correct.  Instead, we should do that only when we don't need
modeset, otherwise, we initialize the two EBA buffers with the buffer address.

Fixes: c6c1f9bc798b ("drm/imx: Add active plane reconfiguration support")
Cc: stable@vger.kernel.org # 4.8
Signed-off-by: Liu Ying <gnuiyl@gmail.com>
Signed-off-by: Philipp Zabel <p.zabel@pengutronix.de>

1 files changed, 2 insertions, 1 deletions

diff --git a/drivers/gpu/drm/imx/ipuv3-plane.c b/drivers/gpu/drm/imx/ipuv3-plane.c
index ce22d0a0ddc8..f5861d9b0df7 100644
--- a/drivers/gpu/drm/imx/ipuv3-plane.c
+++ b/drivers/gpu/drm/imx/ipuv3-plane.c
@@ -108,6 +108,7 @@ static void ipu_plane_atomic_set_base(struct ipu_plane *ipu_plane,
 {
         struct drm_plane *plane = &ipu_plane->base;
         struct drm_plane_state *state = plane->state;
+        struct drm_crtc_state *crtc_state = state->crtc->state;
         struct drm_framebuffer *fb = state->fb;
         unsigned long eba, ubo, vbo;
         int active;
@@ -149,7 +150,7 @@ static void ipu_plane_atomic_set_base(struct ipu_plane *ipu_plane,
                 break;
         }
 
-        if (old_state->fb) {
+        if (!drm_atomic_crtc_needs_modeset(crtc_state)) {
                 active = ipu_idmac_get_current_buffer(ipu_plane->ipu_ch);
                 ipu_cpmem_set_buffer(ipu_plane->ipu_ch, !active, eba);
                 ipu_idmac_select_buffer(ipu_plane->ipu_ch, !active);