6.15-stable review patch. If anyone has any objections, please let me know.
------------------
From: Jason-JH Lin jason-jh.lin@mediatek.com
[ Upstream commit d208261e9f7c66960587b10473081dc1cecbe50b ]
Our hardware registers are set through GCE, not by the CPU. DRM might assume the hardware is disabled immediately after calling atomic_disable() of drm_plane, but it is only truly disabled after the GCE IRQ is triggered.
Additionally, the cursor plane in DRM uses async_commit, so DRM will not wait for vblank and will free the buffer immediately after calling atomic_disable().
To prevent the framebuffer from being freed before the layer disable settings are configured into the hardware, which can cause an IOMMU fault error, a wait_event_timeout has been added to wait for the ddp_cmdq_cb() callback,indicating that the GCE IRQ has been triggered.
Fixes: 2f965be7f900 ("drm/mediatek: apply CMDQ control flow") Signed-off-by: Jason-JH Lin jason-jh.lin@mediatek.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/20250624113223.443... Signed-off-by: Chun-Kuang Hu chunkuang.hu@kernel.org Signed-off-by: Sasha Levin sashal@kernel.org --- drivers/gpu/drm/mediatek/mtk_crtc.c | 33 ++++++++++++++++++++++++++++ drivers/gpu/drm/mediatek/mtk_crtc.h | 1 + drivers/gpu/drm/mediatek/mtk_plane.c | 5 +++++ 3 files changed, 39 insertions(+)
diff --git a/drivers/gpu/drm/mediatek/mtk_crtc.c b/drivers/gpu/drm/mediatek/mtk_crtc.c index 8f6fba4217ece..6916c8925b412 100644 --- a/drivers/gpu/drm/mediatek/mtk_crtc.c +++ b/drivers/gpu/drm/mediatek/mtk_crtc.c @@ -719,6 +719,39 @@ int mtk_crtc_plane_check(struct drm_crtc *crtc, struct drm_plane *plane, return 0; }
+void mtk_crtc_plane_disable(struct drm_crtc *crtc, struct drm_plane *plane) +{ +#if IS_REACHABLE(CONFIG_MTK_CMDQ) + struct mtk_crtc *mtk_crtc = to_mtk_crtc(crtc); + struct mtk_plane_state *plane_state = to_mtk_plane_state(plane->state); + int i; + + /* no need to wait for disabling the plane by CPU */ + if (!mtk_crtc->cmdq_client.chan) + return; + + if (!mtk_crtc->enabled) + return; + + /* set pending plane state to disabled */ + for (i = 0; i < mtk_crtc->layer_nr; i++) { + struct drm_plane *mtk_plane = &mtk_crtc->planes[i]; + struct mtk_plane_state *mtk_plane_state = to_mtk_plane_state(mtk_plane->state); + + if (mtk_plane->index == plane->index) { + memcpy(mtk_plane_state, plane_state, sizeof(*plane_state)); + break; + } + } + mtk_crtc_update_config(mtk_crtc, false); + + /* wait for planes to be disabled by CMDQ */ + wait_event_timeout(mtk_crtc->cb_blocking_queue, + mtk_crtc->cmdq_vblank_cnt == 0, + msecs_to_jiffies(500)); +#endif +} + void mtk_crtc_async_update(struct drm_crtc *crtc, struct drm_plane *plane, struct drm_atomic_state *state) { diff --git a/drivers/gpu/drm/mediatek/mtk_crtc.h b/drivers/gpu/drm/mediatek/mtk_crtc.h index 388e900b6f4de..828f109b83e78 100644 --- a/drivers/gpu/drm/mediatek/mtk_crtc.h +++ b/drivers/gpu/drm/mediatek/mtk_crtc.h @@ -21,6 +21,7 @@ int mtk_crtc_create(struct drm_device *drm_dev, const unsigned int *path, unsigned int num_conn_routes); int mtk_crtc_plane_check(struct drm_crtc *crtc, struct drm_plane *plane, struct mtk_plane_state *state); +void mtk_crtc_plane_disable(struct drm_crtc *crtc, struct drm_plane *plane); void mtk_crtc_async_update(struct drm_crtc *crtc, struct drm_plane *plane, struct drm_atomic_state *plane_state); struct device *mtk_crtc_dma_dev_get(struct drm_crtc *crtc); diff --git a/drivers/gpu/drm/mediatek/mtk_plane.c b/drivers/gpu/drm/mediatek/mtk_plane.c index 655106bbb76d3..59edbe26f01ee 100644 --- a/drivers/gpu/drm/mediatek/mtk_plane.c +++ b/drivers/gpu/drm/mediatek/mtk_plane.c @@ -285,9 +285,14 @@ static void mtk_plane_atomic_disable(struct drm_plane *plane, struct drm_plane_state *new_state = drm_atomic_get_new_plane_state(state, plane); struct mtk_plane_state *mtk_plane_state = to_mtk_plane_state(new_state); + struct drm_plane_state *old_state = drm_atomic_get_old_plane_state(state, + plane); + mtk_plane_state->pending.enable = false; wmb(); /* Make sure the above parameter is set before update */ mtk_plane_state->pending.dirty = true; + + mtk_crtc_plane_disable(old_state->crtc, plane); }
static void mtk_plane_atomic_update(struct drm_plane *plane,