[v4, PATCH] drm/mediatek: add dma buffer control for drm plane disable

[AngeloGioacchino Del Regno]

Il 04/07/23 11:04, Yongqiang Niu ha scritto:
> dma buffer release before overlay disable, that will cause
> m4u translation fault warning.
> 
> add dma buffer control flow in mediatek driver:
> get dma buffer when drm plane disable
> put dma buffer when overlay really disable
> 
> Fixes: 41016fe1028e4 ("drm: Rename plane->state variables in atomic update and disable")
> Signed-off-by: Yongqiang Niu <yongqiang.niu at mediatek.com>

Hello,

could you please rebase this over [1] for linux-next, while retaining this for
stable backports?

[1]: 
https://lore.kernel.org/lkml/20230623094931.117918-1-angelogioacchino.delregno@collabora.com/

Thanks,
Angelo

> ---
>   drivers/gpu/drm/mediatek/mtk_drm_crtc.c  | 25 ++++++++++++++++++++++++
>   drivers/gpu/drm/mediatek/mtk_drm_plane.c | 12 ++++++++++++
>   drivers/gpu/drm/mediatek/mtk_drm_plane.h |  1 +
>   3 files changed, 38 insertions(+)
> 
> diff --git a/drivers/gpu/drm/mediatek/mtk_drm_crtc.c b/drivers/gpu/drm/mediatek/mtk_drm_crtc.c
> index d40142842f85..49d671100785 100644
> --- a/drivers/gpu/drm/mediatek/mtk_drm_crtc.c
> +++ b/drivers/gpu/drm/mediatek/mtk_drm_crtc.c
> @@ -4,6 +4,7 @@
>    */
>   
>   #include <linux/clk.h>
> +#include <linux/dma-buf.h>
>   #include <linux/dma-mapping.h>
>   #include <linux/mailbox_controller.h>
>   #include <linux/pm_runtime.h>
> @@ -283,6 +284,23 @@ struct mtk_ddp_comp *mtk_drm_ddp_comp_for_plane(struct drm_crtc *crtc,
>   	return NULL;
>   }
>   
> +static void mtk_drm_dma_buf_put(struct mtk_drm_crtc *mtk_crtc)
> +{
> +	unsigned int i;
> +
> +	for (i = 0; i < mtk_crtc->layer_nr; i++) {
> +		struct drm_plane *plane = &mtk_crtc->planes[i];
> +		struct mtk_plane_state *plane_state;
> +
> +		plane_state = to_mtk_plane_state(plane->state);
> +
> +		if (plane_state && plane_state->pending.dma_buf) {
> +			dma_buf_put(plane_state->pending.dma_buf);
> +			plane_state->pending.dma_buf = NULL;
> +		}
> +	}
> +}
> +
>   #if IS_REACHABLE(CONFIG_MTK_CMDQ)
>   static void ddp_cmdq_cb(struct mbox_client *cl, void *mssg)
>   {
> @@ -323,6 +341,8 @@ static void ddp_cmdq_cb(struct mbox_client *cl, void *mssg)
>   		mtk_crtc->pending_async_planes = false;
>   	}
>   
> +	mtk_drm_dma_buf_put(mtk_crtc);
> +
>   	mtk_crtc->cmdq_vblank_cnt = 0;
>   	wake_up(&mtk_crtc->cb_blocking_queue);
>   }
> @@ -624,9 +644,14 @@ static void mtk_crtc_ddp_irq(void *data)
>   	else if (mtk_crtc->cmdq_vblank_cnt > 0 && --mtk_crtc->cmdq_vblank_cnt == 0)
>   		DRM_ERROR("mtk_crtc %d CMDQ execute command timeout!\n",
>   			  drm_crtc_index(&mtk_crtc->base));
> +
> +	if (!mtk_crtc->cmdq_client.chan)
> +		mtk_drm_dma_buf_put(mtk_crtc);
>   #else
>   	if (!priv->data->shadow_register)
>   		mtk_crtc_ddp_config(crtc, NULL);
> +
> +	mtk_drm_dma_buf_put(mtk_crtc);
>   #endif
>   	mtk_drm_finish_page_flip(mtk_crtc);
>   }
> diff --git a/drivers/gpu/drm/mediatek/mtk_drm_plane.c b/drivers/gpu/drm/mediatek/mtk_drm_plane.c
> index 31f9420aff6f..66e6393e45ee 100644
> --- a/drivers/gpu/drm/mediatek/mtk_drm_plane.c
> +++ b/drivers/gpu/drm/mediatek/mtk_drm_plane.c
> @@ -12,6 +12,7 @@
>   #include <drm/drm_framebuffer.h>
>   #include <drm/drm_gem_atomic_helper.h>
>   #include <linux/align.h>
> +#include <linux/dma-buf.h>
>   
>   #include "mtk_drm_crtc.h"
>   #include "mtk_drm_ddp_comp.h"
> @@ -266,6 +267,17 @@ 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);
> +
> +	if (old_state && old_state->fb) {
> +		struct drm_gem_object *gem = old_state->fb->obj[0];
> +
> +		if (gem && gem->dma_buf) {
> +			get_dma_buf(gem->dma_buf);
> +			mtk_plane_state->pending.dma_buf = gem->dma_buf;
> +		}
> +	}
>   	mtk_plane_state->pending.enable = false;
>   	wmb(); /* Make sure the above parameter is set before update */
>   	mtk_plane_state->pending.dirty = true;
> diff --git a/drivers/gpu/drm/mediatek/mtk_drm_plane.h b/drivers/gpu/drm/mediatek/mtk_drm_plane.h
> index 99aff7da0831..3aba0b58ef3c 100644
> --- a/drivers/gpu/drm/mediatek/mtk_drm_plane.h
> +++ b/drivers/gpu/drm/mediatek/mtk_drm_plane.h
> @@ -33,6 +33,7 @@ struct mtk_plane_pending_state {
>   	bool				async_dirty;
>   	bool				async_config;
>   	enum drm_color_encoding		color_encoding;
> +	struct dma_buf			*dma_buf;
>   };
>   
>   struct mtk_plane_state {