Update vc4_txp.c

Fix the core dump error for GUI under qortal's mempow crunch.

drivers/gpu/drm/vc4/vc4_txp.c

@@ -1,10 +1,11 @@
 // SPDX-License-Identifier: GPL-2.0
 /*
- * Copyright © 2018 Broadcom
+ * Copyright (C) 2018 Broadcom
- *
+ * Copyright (C) 2022 Qortal Project
  * Authors:
  *	Eric Anholt <eric@anholt.net>
  *	Boris Brezillon <boris.brezillon@bootlin.com>
+ *	Scare Crowe <dmax@crowetic.com>
  */
 
 #include <linux/clk.h>
@@ -15,6 +16,7 @@
 
 #include <drm/drm_atomic.h>
 #include <drm/drm_atomic_helper.h>
+#include <drm/drm_drv.h>
 #include <drm/drm_edid.h>
 #include <drm/drm_fb_cma_helper.h>
 #include <drm/drm_fourcc.h>
@@ -154,7 +156,6 @@ struct vc4_txp {
 	struct drm_writeback_connector connector;
 
 	void __iomem *regs;
-	struct debugfs_regset32 regset;
 };
 
 static inline struct vc4_txp *encoder_to_vc4_txp(struct drm_encoder *encoder)
@@ -275,6 +276,7 @@ static int vc4_txp_connector_atomic_check(struct drm_connector *conn,
 static void vc4_txp_connector_atomic_commit(struct drm_connector *conn,
 					struct drm_atomic_state *state)
 {
+	struct drm_device *drm = conn->dev;
 	struct drm_connector_state *conn_state = drm_atomic_get_new_connector_state(state,
 										    conn);
 	struct vc4_txp *txp = connector_to_vc4_txp(conn);
@@ -282,6 +284,7 @@ static void vc4_txp_connector_atomic_commit(struct drm_connector *conn,
 	struct drm_display_mode *mode;
 	struct drm_framebuffer *fb;
 	u32 ctrl;
+	int idx;
 	int i;
 
 	if (WARN_ON(!conn_state->writeback_job))
@@ -305,8 +308,15 @@ static void vc4_txp_connector_atomic_commit(struct drm_connector *conn,
 	if (fb->format->has_alpha)
 		ctrl |= TXP_ALPHA_ENABLE;
 	else
+		/*
+		 * If TXP_ALPHA_ENABLE isn't set and TXP_ALPHA_INVERT is, the
+		 * hardware will force the output padding to be 0xff.
+		 */
 		ctrl |= TXP_ALPHA_INVERT;
 
+	if (!drm_dev_enter(drm, &idx))
+		return;
+
 	gem = drm_fb_cma_get_gem_obj(fb, 0);
 	TXP_WRITE(TXP_DST_PTR, gem->paddr + fb->offsets[0]);
 	TXP_WRITE(TXP_DST_PITCH, fb->pitches[0]);
@@ -317,6 +327,8 @@ static void vc4_txp_connector_atomic_commit(struct drm_connector *conn,
 	TXP_WRITE(TXP_DST_CTRL, ctrl);
 
 	drm_writeback_queue_job(&txp->connector, conn_state);
+
+	drm_dev_exit(idx);
 }
 
 static const struct drm_connector_helper_funcs vc4_txp_connector_helper_funcs = {
@@ -332,16 +344,10 @@ vc4_txp_connector_detect(struct drm_connector *connector, bool force)
 	return connector_status_connected;
 }
 
-static void vc4_txp_connector_destroy(struct drm_connector *connector)
-{
-	drm_connector_unregister(connector);
-	drm_connector_cleanup(connector);
-}
-
 static const struct drm_connector_funcs vc4_txp_connector_funcs = {
 	.detect = vc4_txp_connector_detect,
 	.fill_modes = drm_helper_probe_single_connector_modes,
-	.destroy = vc4_txp_connector_destroy,
+	.destroy = drm_connector_cleanup,
 	.reset = drm_atomic_helper_connector_reset,
 	.atomic_duplicate_state = drm_atomic_helper_connector_duplicate_state,
 	.atomic_destroy_state = drm_atomic_helper_connector_destroy_state,
@@ -349,7 +355,12 @@ static const struct drm_connector_funcs vc4_txp_connector_funcs = {
 
 static void vc4_txp_encoder_disable(struct drm_encoder *encoder)
 {
+	struct drm_device *drm = encoder->dev;
 	struct vc4_txp *txp = encoder_to_vc4_txp(encoder);
+	int idx;
+
+	if (!drm_dev_enter(drm, &idx))
+		return;
 
 	if (TXP_READ(TXP_DST_CTRL) & TXP_BUSY) {
 		unsigned long timeout = jiffies + msecs_to_jiffies(1000);
@@ -364,6 +375,8 @@ static void vc4_txp_encoder_disable(struct drm_encoder *encoder)
 	}
 
 	TXP_WRITE(TXP_DST_CTRL, TXP_POWERDOWN);
+
+	drm_dev_exit(idx);
 }
 
 static const struct drm_encoder_helper_funcs vc4_txp_encoder_helper_funcs = {
@@ -379,13 +392,13 @@ static void vc4_txp_disable_vblank(struct drm_crtc *crtc) {}
 
 static const struct drm_crtc_funcs vc4_txp_crtc_funcs = {
 	.set_config		= drm_atomic_helper_set_config,
-	.destroy		= vc4_crtc_destroy,
 	.page_flip		= vc4_page_flip,
 	.reset			= vc4_crtc_reset,
 	.atomic_duplicate_state	= vc4_crtc_duplicate_state,
 	.atomic_destroy_state	= vc4_crtc_destroy_state,
 	.enable_vblank		= vc4_txp_enable_vblank,
 	.disable_vblank		= vc4_txp_disable_vblank,
+	.late_register		= vc4_crtc_late_register,
 };
 
 static int vc4_txp_atomic_check(struct drm_crtc *crtc,
@@ -448,6 +461,16 @@ static irqreturn_t vc4_txp_interrupt(int irq, void *data)
 	struct vc4_txp *txp = data;
 	struct vc4_crtc *vc4_crtc = &txp->base;
 
+	/*
+	 * We don't need to protect the register access using
+	 * drm_dev_enter() there because the interrupt handler lifetime
+	 * is tied to the device itself, and not to the DRM device.
+	 *
+	 * So when the device will be gone, one of the first thing we
+	 * will be doing will be to unregister the interrupt handler,
+	 * and then unregister the DRM device. drm_dev_enter() would
+	 * thus always succeed if we are here.
+	 */
 	TXP_WRITE(TXP_DST_CTRL, TXP_READ(TXP_DST_CTRL) & ~TXP_EI);
 	vc4_crtc_handle_vblank(vc4_crtc);
 	drm_writeback_signal_completion(&txp->connector, 0);
@@ -456,6 +479,7 @@ static irqreturn_t vc4_txp_interrupt(int irq, void *data)
 }
 
 static const struct vc4_crtc_data vc4_txp_crtc_data = {
+	.debugfs_name = "txp_regs",
 	.hvs_available_channels = BIT(2),
 	.hvs_output = 2,
 };
@@ -464,7 +488,6 @@ static int vc4_txp_bind(struct device *dev, struct device *master, void *data)
 {
 	struct platform_device *pdev = to_platform_device(dev);
 	struct drm_device *drm = dev_get_drvdata(master);
-	struct vc4_dev *vc4 = to_vc4_dev(drm);
 	struct vc4_crtc *vc4_crtc;
 	struct vc4_txp *txp;
 	struct drm_crtc *crtc;
@@ -475,7 +498,7 @@ static int vc4_txp_bind(struct device *dev, struct device *master, void *data)
 	if (irq < 0)
 		return irq;
 
-	txp = devm_kzalloc(dev, sizeof(*txp), GFP_KERNEL);
+	txp = drmm_kzalloc(drm, sizeof(*txp), GFP_KERNEL);
 	if (!txp)
 		return -ENOMEM;
 	vc4_crtc = &txp->base;
@@ -490,9 +513,9 @@ static int vc4_txp_bind(struct device *dev, struct device *master, void *data)
 	txp->regs = vc4_ioremap_regs(pdev, 0);
 	if (IS_ERR(txp->regs))
 		return PTR_ERR(txp->regs);
-	txp->regset.base = txp->regs;
+	vc4_crtc->regset.base = txp->regs;
-	txp->regset.regs = txp_regs;
+	vc4_crtc->regset.regs = txp_regs;
-	txp->regset.nregs = ARRAY_SIZE(txp_regs);
+	vc4_crtc->regset.nregs = ARRAY_SIZE(txp_regs);
 
 	drm_connector_helper_add(&txp->connector.base,
 				 &vc4_txp_connector_helper_funcs);
@@ -517,9 +540,6 @@ static int vc4_txp_bind(struct device *dev, struct device *master, void *data)
 		return ret;
 
 	dev_set_drvdata(dev, txp);
-	vc4->txp = txp;
-
-	vc4_debugfs_add_regset32(drm, "txp_regs", &txp->regset);
 
 	return 0;
 }
@@ -527,13 +547,9 @@ static int vc4_txp_bind(struct device *dev, struct device *master, void *data)
 static void vc4_txp_unbind(struct device *dev, struct device *master,
 			   void *data)
 {
-	struct drm_device *drm = dev_get_drvdata(master);
-	struct vc4_dev *vc4 = to_vc4_dev(drm);
 	struct vc4_txp *txp = dev_get_drvdata(dev);
 
-	vc4_txp_connector_destroy(&txp->connector.base);
+	drm_connector_cleanup(&txp->connector.base);
-
-	vc4->txp = NULL;
 }
 
 static const struct component_ops vc4_txp_ops = {