imx-drm: ipu-dp: split disabling the DP foreground channel from disabling the DP module

The former has to be done before disabling the DMFC, the latter has to be
done afterwards. Otherwise the DMFC FIFOs never get cleared properly.
Signed-off-by: Philipp Zabel <p.zabel@pengutronix.de>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>

drivers/staging/imx-drm/ipu-v3/imx-ipu-v3.h

@@ -153,8 +153,10 @@ void ipu_dmfc_put(struct dmfc_channel *dmfc);
 
 struct ipu_dp *ipu_dp_get(struct ipu_soc *ipu, unsigned int flow);
 void ipu_dp_put(struct ipu_dp *);
+int ipu_dp_enable(struct ipu_soc *ipu);
 int ipu_dp_enable_channel(struct ipu_dp *dp);
 void ipu_dp_disable_channel(struct ipu_dp *dp);
+void ipu_dp_disable(struct ipu_soc *ipu);
 int ipu_dp_setup_channel(struct ipu_dp *dp,
 		enum ipu_color_space in, enum ipu_color_space out);
 int ipu_dp_set_window_pos(struct ipu_dp *, u16 x_pos, u16 y_pos);

drivers/staging/imx-drm/ipu-v3/ipu-dp.c

@@ -215,10 +215,9 @@ int ipu_dp_setup_channel(struct ipu_dp *dp,
 }
 EXPORT_SYMBOL_GPL(ipu_dp_setup_channel);
 
-int ipu_dp_enable_channel(struct ipu_dp *dp)
+int ipu_dp_enable(struct ipu_soc *ipu)
 {
-	struct ipu_flow *flow = to_flow(dp);
-	struct ipu_dp_priv *priv = flow->priv;
+	struct ipu_dp_priv *priv = ipu->dp_priv;
 
 	mutex_lock(&priv->mutex);
 
@@ -227,15 +226,28 @@ int ipu_dp_enable_channel(struct ipu_dp *dp)
 
 	priv->use_count++;
 
-	if (dp->foreground) {
-		u32 reg;
+	mutex_unlock(&priv->mutex);
 
-		reg = readl(flow->base + DP_COM_CONF);
-		reg |= DP_COM_CONF_FG_EN;
-		writel(reg, flow->base + DP_COM_CONF);
+	return 0;
+}
+EXPORT_SYMBOL_GPL(ipu_dp_enable);
 
-		ipu_srm_dp_sync_update(priv->ipu);
-	}
+int ipu_dp_enable_channel(struct ipu_dp *dp)
+{
+	struct ipu_flow *flow = to_flow(dp);
+	struct ipu_dp_priv *priv = flow->priv;
+	u32 reg;
+
+	if (!dp->foreground)
+		return 0;
+
+	mutex_lock(&priv->mutex);
+
+	reg = readl(flow->base + DP_COM_CONF);
+	reg |= DP_COM_CONF_FG_EN;
+	writel(reg, flow->base + DP_COM_CONF);
+
+	ipu_srm_dp_sync_update(priv->ipu);
 
 	mutex_unlock(&priv->mutex);
 
@@ -247,25 +259,35 @@ void ipu_dp_disable_channel(struct ipu_dp *dp)
 {
 	struct ipu_flow *flow = to_flow(dp);
 	struct ipu_dp_priv *priv = flow->priv;
+	u32 reg, csc;
+
+	if (!dp->foreground)
+		return;
 
 	mutex_lock(&priv->mutex);
 
-	priv->use_count--;
+	reg = readl(flow->base + DP_COM_CONF);
+	csc = reg & DP_COM_CONF_CSC_DEF_MASK;
+	if (csc == DP_COM_CONF_CSC_DEF_FG)
+		reg &= ~DP_COM_CONF_CSC_DEF_MASK;
 
-	if (dp->foreground) {
-		u32 reg, csc;
+	reg &= ~DP_COM_CONF_FG_EN;
+	writel(reg, flow->base + DP_COM_CONF);
 
-		reg = readl(flow->base + DP_COM_CONF);
-		csc = reg & DP_COM_CONF_CSC_DEF_MASK;
-		if (csc == DP_COM_CONF_CSC_DEF_FG)
-			reg &= ~DP_COM_CONF_CSC_DEF_MASK;
+	writel(0, flow->base + DP_FG_POS);
+	ipu_srm_dp_sync_update(priv->ipu);
 
-		reg &= ~DP_COM_CONF_FG_EN;
-		writel(reg, flow->base + DP_COM_CONF);
+	mutex_unlock(&priv->mutex);
+}
+EXPORT_SYMBOL_GPL(ipu_dp_disable_channel);
 
-		writel(0, flow->base + DP_FG_POS);
-		ipu_srm_dp_sync_update(priv->ipu);
-	}
+void ipu_dp_disable(struct ipu_soc *ipu)
+{
+	struct ipu_dp_priv *priv = ipu->dp_priv;
+
+	mutex_lock(&priv->mutex);
+
+	priv->use_count--;
 
 	if (!priv->use_count)
 		ipu_module_disable(priv->ipu, IPU_CONF_DP_EN);
@@ -275,7 +297,7 @@ void ipu_dp_disable_channel(struct ipu_dp *dp)
 
 	mutex_unlock(&priv->mutex);
 }
-EXPORT_SYMBOL_GPL(ipu_dp_disable_channel);
+EXPORT_SYMBOL_GPL(ipu_dp_disable);
 
 struct ipu_dp *ipu_dp_get(struct ipu_soc *ipu, unsigned int flow)
 {

drivers/staging/imx-drm/ipuv3-plane.c

@@ -239,6 +239,8 @@ int ipu_plane_get_resources(struct ipu_plane *ipu_plane)
 
 void ipu_plane_enable(struct ipu_plane *ipu_plane)
 {
+	if (ipu_plane->dp)
+		ipu_dp_enable(ipu_plane->ipu);
 	ipu_dmfc_enable_channel(ipu_plane->dmfc);
 	ipu_idmac_enable_channel(ipu_plane->ipu_ch);
 	if (ipu_plane->dp)
@@ -257,6 +259,8 @@ void ipu_plane_disable(struct ipu_plane *ipu_plane)
 		ipu_dp_disable_channel(ipu_plane->dp);
 	ipu_idmac_disable_channel(ipu_plane->ipu_ch);
 	ipu_dmfc_disable_channel(ipu_plane->dmfc);
+	if (ipu_plane->dp)
+		ipu_dp_disable(ipu_plane->ipu);
 }
 
 static void ipu_plane_dpms(struct ipu_plane *ipu_plane, int mode)