3 files changed, 40 insertions, 0 deletions

diff --git a/drivers/gpu/drm/meson/meson_plane.c b/drivers/gpu/drm/meson/meson_plane.c
index 8ee2cf9e47cd..6119a0224278 100644
--- a/drivers/gpu/drm/meson/meson_plane.c
+++ b/drivers/gpu/drm/meson/meson_plane.c
@@ -80,6 +80,7 @@
 struct meson_plane {
 	struct drm_plane base;
 	struct meson_drm *priv;
+	bool enabled;
 };
 #define to_meson_plane(x) container_of(x, struct meson_plane, base)
 
@@ -304,6 +305,15 @@ static void meson_plane_atomic_update(struct drm_plane *plane,
 	priv->viu.osd1_stride = fb->pitches[0];
 	priv->viu.osd1_height = fb->height;
 
+	if (!meson_plane->enabled) {
+		/* Reset OSD1 before enabling it on GXL+ SoCs */
+		if (meson_vpu_is_compatible(priv, "amlogic,meson-gxm-vpu") ||
+		    meson_vpu_is_compatible(priv, "amlogic,meson-gxl-vpu"))
+			meson_viu_osd1_reset(priv);
+
+		meson_plane->enabled = true;
+	}
+
 	spin_unlock_irqrestore(&priv->drm->event_lock, flags);
 }
 
@@ -317,6 +327,8 @@ static void meson_plane_atomic_disable(struct drm_plane *plane,
 	writel_bits_relaxed(VPP_OSD1_POSTBLEND, 0,
 			    priv->io_base + _REG(VPP_MISC));
 
+	meson_plane->enabled = false;
+
 }
 
 static const struct drm_plane_helper_funcs meson_plane_helper_funcs = {
diff --git a/drivers/gpu/drm/meson/meson_viu.c b/drivers/gpu/drm/meson/meson_viu.c
index 2dffb987ec65..0ba87ff95530 100644
--- a/drivers/gpu/drm/meson/meson_viu.c
+++ b/drivers/gpu/drm/meson/meson_viu.c
@@ -296,6 +296,33 @@ static void meson_viu_load_matrix(struct meson_drm *priv)
 				 true);
 }
 
+/* VIU OSD1 Reset as workaround for GXL+ Alpha OSD Bug */
+void meson_viu_osd1_reset(struct meson_drm *priv)
+{
+	uint32_t osd1_fifo_ctrl_stat, osd1_ctrl_stat2;
+
+	/* Save these 2 registers state */
+	osd1_fifo_ctrl_stat = readl_relaxed(
+				priv->io_base + _REG(VIU_OSD1_FIFO_CTRL_STAT));
+	osd1_ctrl_stat2 = readl_relaxed(
+				priv->io_base + _REG(VIU_OSD1_CTRL_STAT2));
+
+	/* Reset OSD1 */
+	writel_bits_relaxed(BIT(0), BIT(0),
+			    priv->io_base + _REG(VIU_SW_RESET));
+	writel_bits_relaxed(BIT(0), 0,
+			    priv->io_base + _REG(VIU_SW_RESET));
+
+	/* Rewrite these registers state lost in the reset */
+	writel_relaxed(osd1_fifo_ctrl_stat,
+		       priv->io_base + _REG(VIU_OSD1_FIFO_CTRL_STAT));
+	writel_relaxed(osd1_ctrl_stat2,
+		       priv->io_base + _REG(VIU_OSD1_CTRL_STAT2));
+
+	/* Reload the conversion matrix */
+	meson_viu_load_matrix(priv);
+}
+
 void meson_viu_init(struct meson_drm *priv)
 {
 	uint32_t reg;
diff --git a/drivers/gpu/drm/meson/meson_viu.h b/drivers/gpu/drm/meson/meson_viu.h
index 073b1910bd1b..0f84bddd2ff0 100644
--- a/drivers/gpu/drm/meson/meson_viu.h
+++ b/drivers/gpu/drm/meson/meson_viu.h
@@ -59,6 +59,7 @@
 #define OSD_REPLACE_EN		BIT(14)
 #define OSD_REPLACE_SHIFT	6
 
+void meson_viu_osd1_reset(struct meson_drm *priv);
 void meson_viu_init(struct meson_drm *priv);
 
 #endif /* __MESON_VIU_H */