linux-kernel - [PATCH] drm/mediatek: Do not overwrite user state rotation value.

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Date:   Wed, 27 Oct 2021 12:34:31 -0400
From:   Mark Yacoub <markyacoub@...omium.org>
To:     unlisted-recipients:; (no To-header on input)
Cc:     seanpaul@...omium.org, Mark Yacoub <markyacoub@...gle.com>,
        Mark Yacoub <markyacoub@...omium.org>,
        Chun-Kuang Hu <chunkuang.hu@...nel.org>,
        Philipp Zabel <p.zabel@...gutronix.de>,
        David Airlie <airlied@...ux.ie>,
        Daniel Vetter <daniel@...ll.ch>,
        Matthias Brugger <matthias.bgg@...il.com>,
        dri-devel@...ts.freedesktop.org,
        linux-mediatek@...ts.infradead.org,
        linux-arm-kernel@...ts.infradead.org, linux-kernel@...r.kernel.org
Subject: [PATCH] drm/mediatek: Do not overwrite user state rotation value.

From: Mark Yacoub <markyacoub@...gle.com>

[Why]
The rotation property must have a valid bitmask value. 0 isn't a valid
value.
The state should not be overwritten when performing an overlay value
check.

[How]
Do not overwrite state during the check.

Resolves: IGT@..._properties@..._properties-sanity-{atomic,non-atomic}

Signed-off-by: Mark Yacoub <markyacoub@...omium.org>
---
 drivers/gpu/drm/mediatek/mtk_disp_drv.h     |  2 +-
 drivers/gpu/drm/mediatek/mtk_disp_ovl.c     | 20 +++++++-------------
 drivers/gpu/drm/mediatek/mtk_drm_ddp_comp.h |  5 ++---
 3 files changed, 10 insertions(+), 17 deletions(-)

diff --git a/drivers/gpu/drm/mediatek/mtk_disp_drv.h b/drivers/gpu/drm/mediatek/mtk_disp_drv.h
index 86c3068894b11..2fc566964f68e 100644
--- a/drivers/gpu/drm/mediatek/mtk_disp_drv.h
+++ b/drivers/gpu/drm/mediatek/mtk_disp_drv.h
@@ -64,7 +64,7 @@ void mtk_ovl_config(struct device *dev, unsigned int w,
 		    unsigned int h, unsigned int vrefresh,
 		    unsigned int bpc, struct cmdq_pkt *cmdq_pkt);
 int mtk_ovl_layer_check(struct device *dev, unsigned int idx,
-			struct mtk_plane_state *mtk_state);
+			const struct mtk_plane_state *mtk_state);
 void mtk_ovl_layer_config(struct device *dev, unsigned int idx,
 			  struct mtk_plane_state *state,
 			  struct cmdq_pkt *cmdq_pkt);
diff --git a/drivers/gpu/drm/mediatek/mtk_disp_ovl.c b/drivers/gpu/drm/mediatek/mtk_disp_ovl.c
index ea5760f856ec6..13999564304bc 100644
--- a/drivers/gpu/drm/mediatek/mtk_disp_ovl.c
+++ b/drivers/gpu/drm/mediatek/mtk_disp_ovl.c
@@ -190,19 +190,15 @@ unsigned int mtk_ovl_supported_rotations(struct device *dev)
 }
 
 int mtk_ovl_layer_check(struct device *dev, unsigned int idx,
-			struct mtk_plane_state *mtk_state)
+			const struct mtk_plane_state *mtk_state)
 {
-	struct drm_plane_state *state = &mtk_state->base;
-	unsigned int rotation = 0;
+	const struct drm_plane_state *state = &mtk_state->base;
+	unsigned int rotation = drm_rotation_simplify(
+		state->rotation,
+		DRM_MODE_ROTATE_0 | DRM_MODE_REFLECT_X | DRM_MODE_REFLECT_Y);
 
-	rotation = drm_rotation_simplify(state->rotation,
-					 DRM_MODE_ROTATE_0 |
-					 DRM_MODE_REFLECT_X |
-					 DRM_MODE_REFLECT_Y);
-	rotation &= ~DRM_MODE_ROTATE_0;
-
-	/* We can only do reflection, not rotation */
-	if ((rotation & DRM_MODE_ROTATE_MASK) != 0)
+	/* We can only do reflection, not non-zero rotation */
+	if (((rotation & ~DRM_MODE_ROTATE_0) & DRM_MODE_ROTATE_MASK) != 0)
 		return -EINVAL;
 
 	/*
@@ -212,8 +208,6 @@ int mtk_ovl_layer_check(struct device *dev, unsigned int idx,
 	if (state->fb->format->is_yuv && rotation != 0)
 		return -EINVAL;
 
-	state->rotation = rotation;
-
 	return 0;
 }
 
diff --git a/drivers/gpu/drm/mediatek/mtk_drm_ddp_comp.h b/drivers/gpu/drm/mediatek/mtk_drm_ddp_comp.h
index 1b582262b682b..530bdd031933f 100644
--- a/drivers/gpu/drm/mediatek/mtk_drm_ddp_comp.h
+++ b/drivers/gpu/drm/mediatek/mtk_drm_ddp_comp.h
@@ -53,9 +53,8 @@ struct mtk_ddp_comp_funcs {
 	void (*disable_vblank)(struct device *dev);
 	unsigned int (*supported_rotations)(struct device *dev);
 	unsigned int (*layer_nr)(struct device *dev);
-	int (*layer_check)(struct device *dev,
-			   unsigned int idx,
-			   struct mtk_plane_state *state);
+	int (*layer_check)(struct device *dev, unsigned int idx,
+			   const struct mtk_plane_state *state);
 	void (*layer_config)(struct device *dev, unsigned int idx,
 			     struct mtk_plane_state *state,
 			     struct cmdq_pkt *cmdq_pkt);
-- 
2.33.0.1079.g6e70778dc9-goog