2023-12-12 12:20:36

by Shawn Sung

Subject: [PATCH v4 11/17] 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 situations.

Signed-off-by: Hsiao Chien Sung <[email protected]>
---
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 10d23e76acaa..8789442c039f 100644
--- a/drivers/gpu/drm/mediatek/mtk_disp_ovl_adaptor.c
+++ b/drivers/gpu/drm/mediatek/mtk_disp_ovl_adaptor.c
@@ -156,7 +156,7 @@ 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 73c9e3da56a7..e95331c06815 100644
--- a/drivers/gpu/drm/mediatek/mtk_ethdr.c
+++ b/drivers/gpu/drm/mediatek/mtk_ethdr.c
@@ -163,7 +163,12 @@ 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;
}
--
2.18.0

2023-12-12 13:27:26

by AngeloGioacchino Del Regno

Subject: Re: [PATCH v4 11/17] drm/mediatek: Turn off the layers with zero width or height

Il 12/12/23 13:19, Hsiao Chien Sung ha scritto:
> 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 situations.
>
> Signed-off-by: Hsiao Chien Sung <[email protected]>

This commit needs a Fixes tag. Please add the relevant one.

Thanks,
Angelo

> ---
> 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 10d23e76acaa..8789442c039f 100644
> --- a/drivers/gpu/drm/mediatek/mtk_disp_ovl_adaptor.c
> +++ b/drivers/gpu/drm/mediatek/mtk_disp_ovl_adaptor.c
> @@ -156,7 +156,7 @@ 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 73c9e3da56a7..e95331c06815 100644
> --- a/drivers/gpu/drm/mediatek/mtk_ethdr.c
> +++ b/drivers/gpu/drm/mediatek/mtk_ethdr.c
> @@ -163,7 +163,12 @@ 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;
> }