[PATCH v3 06/14] drm/mediatek: Turn off the layers with zero width or height

Hsiao Chien Sung via B4 Relay
2024-06-19T16:39:25Z

From: Hsiao Chien Sung <shawn.sung@mediatek.com>

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>
---
drivers/gpu/drm/mediatek/mtk_disp_ovl_adaptor.c | 2 +-
drivers/gpu/drm/mediatek/mtk_ethdr.c | 7 ++++++-
2 files changed, 7 insertions(+), 2 deletions(-)

diff --git a/drivers/gpu/drm/mediatek/mtk_disp_ovl_adaptor.c b/drivers/gpu/drm/mediatek/mtk_disp_ovl_adaptor.c
index 02dd7dcdfedb..2b62d6475918 100644
--- 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 5c52e514ae30..bf5826b7e776 100644
--- 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;
}

--
Git-146)