drm/mediatek: Fix iommu fault during crtc enabling

[ Upstream commit 53412dc2905401207f264dc30890f6b9e41524a6 ]

The difference between drm_atomic_helper_commit_tail() and
drm_atomic_helper_commit_tail_rpm() is
drm_atomic_helper_commit_tail() will commit plane first and
then enable crtc, drm_atomic_helper_commit_tail_rpm() will
enable crtc first and then commit plane.

Before mediatek-drm enables crtc, the power and clk required
by OVL have not been turned on, so the commit plane cannot be
committed before crtc is enabled. That means OVL layer should
not be enabled before crtc is enabled.
Therefore, the atomic_commit_tail of mediatek-drm is hooked with
drm_atomic_helper_commit_tail_rpm().

Another reason is that the plane_state of drm_atomic_state is not
synchronized with the plane_state stored in mtk_crtc during crtc enablng,
so just set all planes to disabled.

Fixes: 119f5173628a ("drm/mediatek: Add DRM Driver for Mediatek SoC MT8173.")
Signed-off-by: Jason-JH.Lin <jason-jh.lin@mediatek.com>
Reviewed-by: Alexandre Mergnat <amergnat@baylibre.com>
Reviewed-by: AngeloGioacchino Del Regno <angelogioacchino.delregno@collabora.com>
Reviewed-by: CK Hu <ck.hu@mediatek.com>
Link: https://patchwork.kernel.org/project/linux-mediatek/patch/20230809125722.24112-3-jason-jh.lin@mediatek.com/
Signed-off-by: Chun-Kuang Hu <chunkuang.hu@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>

diff --git a/drivers/gpu/drm/mediatek/mtk_drm_crtc.c b/drivers/gpu/drm/mediatek/mtk_drm_crtc.c
index b6fa4ad..0a511d7 100644 (file)
--- a/drivers/gpu/drm/mediatek/mtk_drm_crtc.c
+++ b/drivers/gpu/drm/mediatek/mtk_drm_crtc.c
@@ -408,6 +408,9 @@ static int mtk_crtc_ddp_hw_init(struct mtk_drm_crtc *mtk_crtc)
                unsigned int local_layer;
 
                plane_state = to_mtk_plane_state(plane->state);
+
+               /* should not enable layer before crtc enabled */
+               plane_state->pending.enable = false;
                comp = mtk_drm_ddp_comp_for_plane(crtc, plane, &local_layer);
                if (comp)
                        mtk_ddp_comp_layer_config(comp, local_layer,