drm/exynos: fix vblank bug.

In case that vblank_disable_allowed is 1, the problem that manager->pipe
could be -1 at vsync interrupt handler could be induced so this patch fixes
that.
Signed-off-by: Inki Dae <inki.dae@samsung.com>
Signed-off-by: Kyungmin Park <kyungmin.park@samsung.com>

drivers/gpu/drm/exynos/exynos_drm_fimd.c

@@ -447,7 +447,9 @@ static void fimd_win_commit(struct device *dev)
 static void fimd_win_disable(struct device *dev)
 {
 	struct fimd_context *ctx = get_fimd_context(dev);
-	struct fimd_win_data *win_data;
+	struct exynos_drm_subdrv *subdrv = &ctx->subdrv;
+	struct drm_device *drm_dev = subdrv->drm_dev;
+	struct exynos_drm_manager *manager = &subdrv->manager;
 	int win = ctx->default_win;
 	u32 val;
 
@@ -456,8 +458,6 @@ static void fimd_win_disable(struct device *dev)
 	if (win < 0 || win > WINDOWS_NR)
 		return;
 
-	win_data = &ctx->win_data[win];
-
 	/* protect windows */
 	val = readl(ctx->regs + SHADOWCON);
 	val |= SHADOWCON_WINx_PROTECT(win);
@@ -473,6 +473,29 @@ static void fimd_win_disable(struct device *dev)
 	val &= ~SHADOWCON_CHx_ENABLE(win);
 	val &= ~SHADOWCON_WINx_PROTECT(win);
 	writel(val, ctx->regs + SHADOWCON);
+
+	/* fimd dma off. */
+	val = readl(ctx->regs + VIDCON0);
+	val &= ~(VIDCON0_ENVID | VIDCON0_ENVID_F);
+	writel(val, ctx->regs + VIDCON0);
+
+	/*
+	 * if vblank is enabled status with dma off then
+	 * it disables vsync interrupt.
+	 */
+	if (drm_dev->vblank_enabled[manager->pipe] &&
+			atomic_read(&drm_dev->vblank_refcount[manager->pipe])) {
+		drm_vblank_put(drm_dev, manager->pipe);
+
+		/*
+		 * if vblank_disable_allowed is 0 then disable vsync interrupt
+		 * right now else the vsync interrupt would be disabled by drm
+		 * timer once a current process gives up ownershop of
+		 * vblank event.
+		 */
+		if (!drm_dev->vblank_disable_allowed)
+			drm_vblank_off(drm_dev, manager->pipe);
+	}
 }
 
 static struct exynos_drm_overlay_ops fimd_overlay_ops = {
@@ -528,6 +551,16 @@ static irqreturn_t fimd_irq_handler(int irq, void *dev_id)
 		/* VSYNC interrupt */
 		writel(VIDINTCON1_INT_FRAME, ctx->regs + VIDINTCON1);
 
+	/*
+	 * in case that vblank_disable_allowed is 1, it could induce
+	 * the problem that manager->pipe could be -1 because with
+	 * disable callback, vsync interrupt isn't disabled and at this moment,
+	 * vsync interrupt could occur. the vsync interrupt would be disabled
+	 * by timer handler later.
+	 */
+	if (manager->pipe == -1)
+		return IRQ_HANDLED;
+
 	drm_handle_vblank(drm_dev, manager->pipe);
 	fimd_finish_pageflip(drm_dev, manager->pipe);
 
@@ -548,13 +581,6 @@ static int fimd_subdrv_probe(struct drm_device *drm_dev, struct device *dev)
 	 */
 	drm_dev->irq_enabled = 1;
 
-	/*
-	 * with vblank_disable_allowed = 1, vblank interrupt will be disabled
-	 * by drm timer once a current process gives up ownership of
-	 * vblank event.(drm_vblank_put function was called)
-	 */
-	drm_dev->vblank_disable_allowed = 1;
-
 	return 0;
 }