drm/tilcdc: Fix cpufreq transition related race + cleanup

index f8892e9..882d9b5 100644
@@ -184,10 +184,14 @@ static int cpufreq_transition(struct notifier_block *nb,
 {
 	struct tilcdc_drm_private *priv = container_of(nb,
 			struct tilcdc_drm_private, freq_transition);
+	struct drm_mode_config *config = &priv->dev->mode_config;
+
 	if (val == CPUFREQ_POSTCHANGE) {
 		if (priv->lcd_fck_rate != clk_get_rate(priv->clk)) {
+			mutex_lock(&config->mutex);
 			priv->lcd_fck_rate = clk_get_rate(priv->clk);
 			tilcdc_crtc_update_clk(priv->crtc);
+			mutex_unlock(&config->mutex);
 		}
 	}
 

@@ -251,6 +255,7 @@ static int tilcdc_load(struct drm_device *dev, unsigned long flags)
 	}
 
 	dev->dev_private = priv;
+	priv->dev = dev;
 
 	priv->is_componentized =
 		tilcdc_get_external_components(dev->dev, NULL) > 0;

index a6e5e6d..6caecfc 100644
@@ -49,6 +49,8 @@
 struct tilcdc_drm_private {
 	void __iomem *mmio;
 
+	struct drm_device *dev;
+
 	struct clk *clk;         /* functional clock */
 	int rev;                 /* IP revision */
 

index 84b36fd..f9e3da9 100644
@@ -35,6 +35,8 @@ struct tilcdc_crtc {
 	bool frame_done;
 	spinlock_t irq_lock;
 
+	unsigned int lcd_fck_rate;
+
 	ktime_t last_vblank;
 
 	struct drm_framebuffer *curr_fb;

@@ -324,6 +326,37 @@ static bool tilcdc_crtc_mode_fixup(struct drm_crtc *crtc,
 	return true;
 }
 
+static void tilcdc_crtc_set_clk(struct drm_crtc *crtc)
+{
+	struct drm_device *dev = crtc->dev;
+	struct tilcdc_drm_private *priv = dev->dev_private;
+	struct tilcdc_crtc *tilcdc_crtc = to_tilcdc_crtc(crtc);
+	const unsigned clkdiv = 2; /* using a fixed divider of 2 */
+	int ret;
+
+	/* mode.clock is in KHz, set_rate wants parameter in Hz */
+	ret = clk_set_rate(priv->clk, crtc->mode.clock * 1000 * clkdiv);
+	if (ret < 0) {
+		dev_err(dev->dev, "failed to set display clock rate to: %d\n",
+			crtc->mode.clock);
+		return;
+	}
+
+	tilcdc_crtc->lcd_fck_rate = clk_get_rate(priv->clk);
+
+	DBG("lcd_clk=%u, mode clock=%d, div=%u",
+	    tilcdc_crtc->lcd_fck_rate, crtc->mode.clock, clkdiv);
+
+	/* Configure the LCD clock divisor. */
+	tilcdc_write(dev, LCDC_CTRL_REG, LCDC_CLK_DIVISOR(clkdiv) |
+		     LCDC_RASTER_MODE);
+
+	if (priv->rev == 2)
+		tilcdc_set(dev, LCDC_CLK_ENABLE_REG,
+				LCDC_V2_DMA_CLK_EN | LCDC_V2_LIDD_CLK_EN |
+				LCDC_V2_CORE_CLK_EN);
+}
+
 static void tilcdc_crtc_mode_set_nofb(struct drm_crtc *crtc)
 {
 	struct tilcdc_crtc *tilcdc_crtc = to_tilcdc_crtc(crtc);

@@ -486,7 +519,7 @@ static void tilcdc_crtc_mode_set_nofb(struct drm_crtc *crtc)
 
 	set_scanout(crtc, fb);
 
-	tilcdc_crtc_update_clk(crtc);
+	tilcdc_crtc_set_clk(crtc);
 
 	crtc->hwmode = crtc->state->adjusted_mode;
 }

@@ -655,41 +688,22 @@ void tilcdc_crtc_update_clk(struct drm_crtc *crtc)
 {
 	struct drm_device *dev = crtc->dev;
 	struct tilcdc_drm_private *priv = dev->dev_private;
-	unsigned long lcd_clk;
-	const unsigned clkdiv = 2; /* using a fixed divider of 2 */
-	int ret;
+	struct tilcdc_crtc *tilcdc_crtc = to_tilcdc_crtc(crtc);
+	struct drm_mode_config *config = &priv->dev->mode_config;
 
-	pm_runtime_get_sync(dev->dev);
+	if (tilcdc_crtc->lcd_fck_rate != clk_get_rate(priv->clk)) {
+		mutex_lock(&config->mutex);
+		if (tilcdc_crtc_is_on(crtc)) {
+			pm_runtime_get_sync(dev->dev);
+			tilcdc_crtc_disable(crtc);
 
-	tilcdc_crtc_disable(crtc);
+			tilcdc_crtc_set_clk(crtc);
 
-	/* mode.clock is in KHz, set_rate wants parameter in Hz */
-	ret = clk_set_rate(priv->clk, crtc->mode.clock * 1000 * clkdiv);
-	if (ret < 0) {
-		dev_err(dev->dev, "failed to set display clock rate to: %d\n",
-				crtc->mode.clock);
-		goto out;
+			tilcdc_crtc_enable(crtc);
+			pm_runtime_put_sync(dev->dev);
+		}
+		mutex_unlock(&config->mutex);
 	}
-
-	lcd_clk = clk_get_rate(priv->clk);
-
-	DBG("lcd_clk=%lu, mode clock=%d, div=%u",
-		lcd_clk, crtc->mode.clock, clkdiv);
-
-	/* Configure the LCD clock divisor. */
-	tilcdc_write(dev, LCDC_CTRL_REG, LCDC_CLK_DIVISOR(clkdiv) |
-			LCDC_RASTER_MODE);
-
-	if (priv->rev == 2)
-		tilcdc_set(dev, LCDC_CLK_ENABLE_REG,
-				LCDC_V2_DMA_CLK_EN | LCDC_V2_LIDD_CLK_EN |
-				LCDC_V2_CORE_CLK_EN);
-
-	if (tilcdc_crtc_is_on(crtc))
-		tilcdc_crtc_enable(crtc);
-
-out:
-	pm_runtime_put_sync(dev->dev);
 }
 
 #define SYNC_LOST_COUNT_LIMIT 50

index 882d9b5..4af58b7 100644
@@ -184,16 +184,9 @@ static int cpufreq_transition(struct notifier_block *nb,
 {
 	struct tilcdc_drm_private *priv = container_of(nb,
 			struct tilcdc_drm_private, freq_transition);
-	struct drm_mode_config *config = &priv->dev->mode_config;
-
-	if (val == CPUFREQ_POSTCHANGE) {
-		if (priv->lcd_fck_rate != clk_get_rate(priv->clk)) {
-			mutex_lock(&config->mutex);
-			priv->lcd_fck_rate = clk_get_rate(priv->clk);
-			tilcdc_crtc_update_clk(priv->crtc);
-			mutex_unlock(&config->mutex);
-		}
-	}
+
+	if (val == CPUFREQ_POSTCHANGE)
+		tilcdc_crtc_update_clk(priv->crtc);
 
 	return 0;
 }

@@ -288,7 +281,6 @@ static int tilcdc_load(struct drm_device *dev, unsigned long flags)
 	}
 
 #ifdef CONFIG_CPU_FREQ
-	priv->lcd_fck_rate = clk_get_rate(priv->clk);
 	priv->freq_transition.notifier_call = cpufreq_transition;
 	ret = cpufreq_register_notifier(&priv->freq_transition,
 			CPUFREQ_TRANSITION_NOTIFIER);

index 6caecfc..fac0733 100644
@@ -76,7 +76,6 @@ struct tilcdc_drm_private {
 
 #ifdef CONFIG_CPU_FREQ
 	struct notifier_block freq_transition;
-	unsigned int lcd_fck_rate;
 #endif
 
 	struct workqueue_struct *wq;

index f9e3da9..ac0a63e 100644
@@ -31,6 +31,7 @@ struct tilcdc_crtc {
 	const struct tilcdc_panel_info *info;
 	struct drm_pending_vblank_event *event;
 	bool enabled;
+	struct mutex enable_lock;
 	wait_queue_head_t frame_done_wq;
 	bool frame_done;
 	spinlock_t irq_lock;

@@ -153,8 +154,10 @@ static void tilcdc_crtc_enable(struct drm_crtc *crtc)
 	struct drm_device *dev = crtc->dev;
 	struct tilcdc_crtc *tilcdc_crtc = to_tilcdc_crtc(crtc);
 
+	mutex_lock(&tilcdc_crtc->enable_lock);
+
 	if (tilcdc_crtc->enabled)
-		return;
+		goto out;
 
 	pm_runtime_get_sync(dev->dev);
 

@@ -169,6 +172,8 @@ static void tilcdc_crtc_enable(struct drm_crtc *crtc)
 	drm_crtc_vblank_on(crtc);
 
 	tilcdc_crtc->enabled = true;
+out:
+	mutex_unlock(&tilcdc_crtc->enable_lock);
 }
 
 void tilcdc_crtc_disable(struct drm_crtc *crtc)

@@ -177,8 +182,10 @@ void tilcdc_crtc_disable(struct drm_crtc *crtc)
 	struct drm_device *dev = crtc->dev;
 	struct tilcdc_drm_private *priv = dev->dev_private;
 
+	mutex_lock(&tilcdc_crtc->enable_lock);
+
 	if (!tilcdc_crtc->enabled)
-		return;
+		goto out;
 
 	tilcdc_crtc->frame_done = false;
 	tilcdc_clear(dev, LCDC_RASTER_CTRL_REG, LCDC_RASTER_ENABLE);

@@ -218,6 +225,8 @@ void tilcdc_crtc_disable(struct drm_crtc *crtc)
 	tilcdc_crtc->last_vblank = ktime_set(0, 0);
 
 	tilcdc_crtc->enabled = false;
+out:
+	mutex_unlock(&tilcdc_crtc->enable_lock);
 }
 
 static bool tilcdc_crtc_is_on(struct drm_crtc *crtc)

@@ -819,6 +828,8 @@ struct drm_crtc *tilcdc_crtc_create(struct drm_device *dev)
 	drm_flip_work_init(&tilcdc_crtc->unref_work,
 			"unref", unref_worker);
 
+	mutex_init(&tilcdc_crtc->enable_lock);
+
 	spin_lock_init(&tilcdc_crtc->irq_lock);
 	INIT_WORK(&tilcdc_crtc->recover_work, tilcdc_crtc_recover_work);