Re: [PATCH RESEND v4 2/2] drm/mediatek: Fix iommu fault during crtc enabling

[Eugen Hristev <eugen.hristev@xxxxxxxxxxxxx>]

Hi Jason,

On 8/7/23 04:51, Jason-JH.Lin wrote:
> The plane_state of drm_atomic_state is not sync to the mtk_plane_state
> stored in mtk_crtc during crtc enabling.
>
> So we need to update the mtk_plane_state stored in mtk_crtc by the
> drm_atomic_state carried from mtk_drm_crtc_atomic_enable().
>
> While updating mtk_plane_state, OVL layer should be disabled when the fb
> in plane_state of drm_atomic_state is NULL.
>
> Fixes: 119f5173628a ("drm/mediatek: Add DRM Driver for Mediatek SoC MT8173.")
> Signed-off-by: Jason-JH.Lin <jason-jh.lin@xxxxxxxxxxxx>
> ---
> Change in RESEND v4:
> Remove redundant plane_state assigning.
> ---
>   drivers/gpu/drm/mediatek/mtk_drm_crtc.c  | 14 ++++++++++----
>   drivers/gpu/drm/mediatek/mtk_drm_plane.c | 11 ++++++++---
>   drivers/gpu/drm/mediatek/mtk_drm_plane.h |  2 ++
>   3 files changed, 20 insertions(+), 7 deletions(-)
>
> diff --git a/drivers/gpu/drm/mediatek/mtk_drm_crtc.c b/drivers/gpu/drm/mediatek/mtk_drm_crtc.c
> index d40142842f85..7db4d6551da7 100644
> --- a/drivers/gpu/drm/mediatek/mtk_drm_crtc.c
> +++ b/drivers/gpu/drm/mediatek/mtk_drm_crtc.c
> @@ -328,7 +328,7 @@ static void ddp_cmdq_cb(struct mbox_client *cl, void *mssg)
>   }
>   #endif
>   
> -static int mtk_crtc_ddp_hw_init(struct mtk_drm_crtc *mtk_crtc)
> +static int mtk_crtc_ddp_hw_init(struct mtk_drm_crtc *mtk_crtc, struct drm_atomic_state *state)
>   {
>   	struct drm_crtc *crtc = &mtk_crtc->base;
>   	struct drm_connector *connector;
> @@ -405,11 +405,17 @@ static int mtk_crtc_ddp_hw_init(struct mtk_drm_crtc *mtk_crtc)
>   	/* Initially configure all planes */
>   	for (i = 0; i < mtk_crtc->layer_nr; i++) {
>   		struct drm_plane *plane = &mtk_crtc->planes[i];
> -		struct mtk_plane_state *plane_state;
> +		struct drm_plane_state *new_state;
> +		struct mtk_plane_state *plane_state = to_mtk_plane_state(plane->state);
>   		struct mtk_ddp_comp *comp;
>   		unsigned int local_layer;
>   
> -		plane_state = to_mtk_plane_state(plane->state);

any reason why you moved the initialization of plane_state at the 
declaration phase ?

> +		/* sync the new plane state from drm_atomic_state */
> +		if (state->planes[i].ptr) {
> +			new_state = drm_atomic_get_new_plane_state(state, state->planes[i].ptr);
Can drm_atomic_get_new_plane_state fail ? and new_state becomes null ?

I see mtk_plane_update_new_state assumes new_state being a correct 
state/pointer.

Regards,

> +			mtk_plane_update_new_state(new_state, plane_state);
> +		}
> +
>   		comp = mtk_drm_ddp_comp_for_plane(crtc, plane, &local_layer);
>   		if (comp)
>   			mtk_ddp_comp_layer_config(comp, local_layer,
> @@ -687,7 +693,7 @@ static void mtk_drm_crtc_atomic_enable(struct drm_crtc *crtc,
>   		return;
>   	}
>   
> -	ret = mtk_crtc_ddp_hw_init(mtk_crtc);
> +	ret = mtk_crtc_ddp_hw_init(mtk_crtc, state);
>   	if (ret) {
>   		pm_runtime_put(comp->dev);
>   		return;
> diff --git a/drivers/gpu/drm/mediatek/mtk_drm_plane.c b/drivers/gpu/drm/mediatek/mtk_drm_plane.c
> index b1a918ffe457..ef4460f98c07 100644
> --- a/drivers/gpu/drm/mediatek/mtk_drm_plane.c
> +++ b/drivers/gpu/drm/mediatek/mtk_drm_plane.c
> @@ -134,8 +134,8 @@ static int mtk_plane_atomic_async_check(struct drm_plane *plane,
>   						   true, true);
>   }
>   
> -static void mtk_plane_update_new_state(struct drm_plane_state *new_state,
> -				       struct mtk_plane_state *mtk_plane_state)
> +void mtk_plane_update_new_state(struct drm_plane_state *new_state,
> +				struct mtk_plane_state *mtk_plane_state)
>   {
>   	struct drm_framebuffer *fb = new_state->fb;
>   	struct drm_gem_object *gem;
> @@ -146,6 +146,11 @@ static void mtk_plane_update_new_state(struct drm_plane_state *new_state,
>   	dma_addr_t hdr_addr = 0;
>   	unsigned int hdr_pitch = 0;
>   
> +	if (!fb) {
> +		mtk_plane_state->pending.enable = false;
> +		return;
> +	}
> +
>   	gem = fb->obj[0];
>   	mtk_gem = to_mtk_gem_obj(gem);
>   	addr = mtk_gem->dma_addr;
> @@ -180,7 +185,7 @@ static void mtk_plane_update_new_state(struct drm_plane_state *new_state,
>   		       fb->format->cpp[0] * (x_offset_in_blocks + 1);
>   	}
>   
> -	mtk_plane_state->pending.enable = true;
> +	mtk_plane_state->pending.enable = new_state->visible;
>   	mtk_plane_state->pending.pitch = pitch;
>   	mtk_plane_state->pending.hdr_pitch = hdr_pitch;
>   	mtk_plane_state->pending.format = format;
> diff --git a/drivers/gpu/drm/mediatek/mtk_drm_plane.h b/drivers/gpu/drm/mediatek/mtk_drm_plane.h
> index 99aff7da0831..0a7d70d13e43 100644
> --- a/drivers/gpu/drm/mediatek/mtk_drm_plane.h
> +++ b/drivers/gpu/drm/mediatek/mtk_drm_plane.h
> @@ -46,6 +46,8 @@ to_mtk_plane_state(struct drm_plane_state *state)
>   	return container_of(state, struct mtk_plane_state, base);
>   }
>   
> +void mtk_plane_update_new_state(struct drm_plane_state *new_state,
> +				struct mtk_plane_state *mtk_plane_state);
>   int mtk_plane_init(struct drm_device *dev, struct drm_plane *plane,
>   		   unsigned long possible_crtcs, enum drm_plane_type type,
>   		   unsigned int supported_rotations, const u32 *formats,