From: Andrzej Hajda <a.hajda@samsung.com>
Date: Wed, 5 Apr 2017 09:28:32 +0200
Subject: drm/exynos/decon5433: move TE handling to DECON
Git-commit: b37d53a0382c03064e6fee3ea1fdc77caf4906c6
Patch-mainline: v4.13-rc1
References: FATE#326289 FATE#326079 FATE#326049 FATE#322398 FATE#326166

DECON is the only user of TE signal, moving all TE related
code to DECON driver allows to precise control of IRQ handlers.
This control allows to fix race between IRQ handler and DECON disable
code - now it is possible to disable DECON during IRQ handling
which can result in kernel crash. Beside race fixing this change
allows further code simplification.

Signed-off-by: Andrzej Hajda <a.hajda@samsung.com>
Signed-off-by: Inki Dae <inki.dae@samsung.com>
Acked-by: Petr Tesarik <ptesarik@suse.com>
---
 drivers/gpu/drm/exynos/exynos5433_drm_decon.c |   94 +++++++++++++++++++-------
 1 file changed, 71 insertions(+), 23 deletions(-)

--- a/drivers/gpu/drm/exynos/exynos5433_drm_decon.c
+++ b/drivers/gpu/drm/exynos/exynos5433_drm_decon.c
@@ -63,6 +63,8 @@ struct decon_context {
 	void __iomem			*addr;
 	struct regmap			*sysreg;
 	struct clk			*clks[ARRAY_SIZE(decon_clks_name)];
+	unsigned int			irq;
+	unsigned int			te_irq;
 	unsigned long			flags;
 	unsigned long			out_type;
 	int				first_win;
@@ -105,6 +107,11 @@ static int decon_enable_vblank(struct ex
 		val |= VIDINTCON0_INTFRMEN | VIDINTCON0_FRAMESEL_FP;
 
 	writel(val, ctx->addr + DECON_VIDINTCON0);
+
+	enable_irq(ctx->irq);
+	if (!(ctx->out_type & I80_HW_TRG))
+		enable_irq(ctx->te_irq);
+
 	set_bit(BIT_IRQS_ENABLED, &ctx->flags);
 
 	return 0;
@@ -118,6 +125,10 @@ static void decon_disable_vblank(struct
 	if (test_bit(BIT_SUSPENDED, &ctx->flags))
 		return;
 
+	if (!(ctx->out_type & I80_HW_TRG))
+		disable_irq_nosync(ctx->te_irq);
+	disable_irq_nosync(ctx->irq);
+
 	writel(0, ctx->addr + DECON_VIDINTCON0);
 }
 
@@ -491,6 +502,10 @@ static void decon_disable(struct exynos_
 	struct decon_context *ctx = crtc->ctx;
 	int i;
 
+	if (!(ctx->out_type & I80_HW_TRG))
+		synchronize_irq(ctx->te_irq);
+	synchronize_irq(ctx->irq);
+
 	if (test_bit(BIT_SUSPENDED, &ctx->flags))
 		return;
 
@@ -513,17 +528,19 @@ static void decon_disable(struct exynos_
 	set_bit(BIT_SUSPENDED, &ctx->flags);
 }
 
-static void decon_te_irq_handler(struct exynos_drm_crtc *crtc)
+static irqreturn_t decon_te_irq_handler(int irq, void *dev_id)
 {
-	struct decon_context *ctx = crtc->ctx;
+	struct decon_context *ctx = dev_id;
 
 	if (!test_bit(BIT_CLKS_ENABLED, &ctx->flags) ||
 	    (ctx->out_type & I80_HW_TRG))
-		return;
+		return IRQ_HANDLED;
 
 	if (test_and_clear_bit(BIT_WIN_UPDATED, &ctx->flags) ||
 	    test_bit(BIT_IRQS_ENABLED, &ctx->flags))
 		decon_set_bits(ctx, DECON_TRIGCON, TRIGCON_SWTRIGCMD, ~0);
+
+	return IRQ_HANDLED;
 }
 
 static void decon_clear_channels(struct exynos_drm_crtc *crtc)
@@ -564,7 +581,6 @@ static const struct exynos_drm_crtc_ops
 	.update_plane		= decon_update_plane,
 	.disable_plane		= decon_disable_plane,
 	.atomic_flush		= decon_atomic_flush,
-	.te_handler		= decon_te_irq_handler,
 };
 
 static int decon_bind(struct device *dev, struct device *master, void *data)
@@ -717,6 +733,31 @@ static const struct of_device_id exynos5
 };
 MODULE_DEVICE_TABLE(of, exynos5433_decon_driver_dt_match);
 
+static int decon_conf_irq(struct decon_context *ctx, const char *name,
+		irq_handler_t handler, unsigned long int flags, bool required)
+{
+	struct platform_device *pdev = to_platform_device(ctx->dev);
+	int ret, irq = platform_get_irq_byname(pdev, name);
+
+	if (irq < 0) {
+		if (irq == -EPROBE_DEFER)
+			return irq;
+		if (required)
+			dev_err(ctx->dev, "cannot get %s IRQ\n", name);
+		else
+			irq = 0;
+		return irq;
+	}
+	irq_set_status_flags(irq, IRQ_NOAUTOEN);
+	ret = devm_request_irq(ctx->dev, irq, handler, flags, "drm_decon", ctx);
+	if (ret < 0) {
+		dev_err(ctx->dev, "IRQ %s request failed\n", name);
+		return ret;
+	}
+
+	return irq;
+}
+
 static int exynos5433_decon_probe(struct platform_device *pdev)
 {
 	struct device *dev = &pdev->dev;
@@ -740,15 +781,6 @@ static int exynos5433_decon_probe(struct
 		ctx->out_type |= IFTYPE_I80;
 	}
 
-	if (ctx->out_type & I80_HW_TRG) {
-		ctx->sysreg = syscon_regmap_lookup_by_phandle(dev->of_node,
-							"samsung,disp-sysreg");
-		if (IS_ERR(ctx->sysreg)) {
-			dev_err(dev, "failed to get system register\n");
-			return PTR_ERR(ctx->sysreg);
-		}
-	}
-
 	for (i = 0; i < ARRAY_SIZE(decon_clks_name); i++) {
 		struct clk *clk;
 
@@ -771,18 +803,34 @@ static int exynos5433_decon_probe(struct
 		return PTR_ERR(ctx->addr);
 	}
 
-	res = platform_get_resource_byname(pdev, IORESOURCE_IRQ,
-			(ctx->out_type & IFTYPE_I80) ? "lcd_sys" : "vsync");
-	if (!res) {
-		dev_err(dev, "cannot find IRQ resource\n");
-		return -ENXIO;
+	if (ctx->out_type & IFTYPE_I80) {
+		ret = decon_conf_irq(ctx, "lcd_sys", decon_irq_handler, 0, true);
+		if (ret < 0)
+			return ret;
+		ctx->irq = ret;
+
+		ret = decon_conf_irq(ctx, "te", decon_te_irq_handler,
+				     IRQF_TRIGGER_RISING, false);
+		if (ret < 0)
+			return ret;
+		if (ret) {
+			ctx->te_irq = ret;
+			ctx->out_type &= ~I80_HW_TRG;
+		}
+	} else {
+		ret = decon_conf_irq(ctx, "vsync", decon_irq_handler, 0, true);
+		if (ret < 0)
+			return ret;
+		ctx->irq = ret;
 	}
 
-	ret = devm_request_irq(dev, res->start, decon_irq_handler, 0,
-			       "drm_decon", ctx);
-	if (ret < 0) {
-		dev_err(dev, "lcd_sys irq request failed\n");
-		return ret;
+	if (ctx->out_type & I80_HW_TRG) {
+		ctx->sysreg = syscon_regmap_lookup_by_phandle(dev->of_node,
+							"samsung,disp-sysreg");
+		if (IS_ERR(ctx->sysreg)) {
+			dev_err(dev, "failed to get system register\n");
+			return PTR_ERR(ctx->sysreg);
+		}
 	}
 
 	platform_set_drvdata(pdev, ctx);