drm/mediatek: Turn off the layers with zero width or height

We found that IGT (Intel GPU Tool) will try to commit layers with
zero width or height and lead to undefined behaviors in hardware.
Disable the layers in such a situation.

Fixes: 453c3364632a ("drm/mediatek: Add ovl_adaptor support for MT8195")
Fixes: d886c0009bd0 ("drm/mediatek: Add ETHDR support for MT8195")
Reviewed-by: CK Hu <ck.hu@mediatek.com>
Reviewed-by: AngeloGioacchino Del Regno <angelogioacchino.delregno@collabora.com>
Fixes: 119f5173628a ("drm/mediatek: Add DRM Driver for Mediatek SoC MT8173.")
Signed-off-by: Hsiao Chien Sung <shawn.sung@mediatek.com>
Link: https://patchwork.kernel.org/project/dri-devel/patch/20240620-igt-v3-6-a9d62d2e2c7e@mediatek.com/
Signed-off-by: Chun-Kuang Hu <chunkuang.hu@kernel.org>

diff --git a/drivers/gpu/drm/mediatek/mtk_disp_ovl_adaptor.c b/drivers/gpu/drm/mediatek/mtk_disp_ovl_adaptor.c
index 02dd7dcdfedb23760760e02a3fdde06e82cbfa0c..2b62d64759181e9a280aa8fee9746bb7d63b1e5c 100644 (file)
--- a/drivers/gpu/drm/mediatek/mtk_disp_ovl_adaptor.c
+++ b/drivers/gpu/drm/mediatek/mtk_disp_ovl_adaptor.c
@@ -158,7 +158,7 @@ void mtk_ovl_adaptor_layer_config(struct device *dev, unsigned int idx,
        merge = ovl_adaptor->ovl_adaptor_comp[OVL_ADAPTOR_MERGE0 + idx];
        ethdr = ovl_adaptor->ovl_adaptor_comp[OVL_ADAPTOR_ETHDR0];
 
-       if (!pending->enable) {
+       if (!pending->enable || !pending->width || !pending->height) {
                mtk_merge_stop_cmdq(merge, cmdq_pkt);
                mtk_mdp_rdma_stop(rdma_l, cmdq_pkt);
                mtk_mdp_rdma_stop(rdma_r, cmdq_pkt);

diff --git a/drivers/gpu/drm/mediatek/mtk_ethdr.c b/drivers/gpu/drm/mediatek/mtk_ethdr.c
index 5c52e514ae301d8d2aea3533cc2dd4d65ddfefe8..bf5826b7e77607d23a652a08d42af7e3b6c4e751 100644 (file)
--- a/drivers/gpu/drm/mediatek/mtk_ethdr.c
+++ b/drivers/gpu/drm/mediatek/mtk_ethdr.c
@@ -160,7 +160,12 @@ void mtk_ethdr_layer_config(struct device *dev, unsigned int idx,
        if (idx >= 4)
                return;
 
-       if (!pending->enable) {
+       if (!pending->enable || !pending->width || !pending->height) {
+               /*
+                * instead of disabling layer with MIX_SRC_CON directly
+                * set the size to 0 to avoid screen shift due to mixer
+                * mode switch (hardware behavior)
+                */
                mtk_ddp_write(cmdq_pkt, 0, &mixer->cmdq_base, mixer->regs, MIX_L_SRC_SIZE(idx));
                return;
        }