BPI-M2C/MPI_DSI/0001-uboot-fix-mipi-panel-probe-reboot.patch

From 9f2a9e624b59f50ad0f4a47a63c659d3af31f30a Mon Sep 17 00:00:00 2001
From: BPI-M2C <bpi-m2c@local>
Date: Sun, 20 Sep 2026 12:00:00 +0800
Subject: [PATCH] uboot: sprd: fix MIPI panel probe failure reboot

When multiple panel nodes are probed, release IOVDD together with the
other panel GPIOs. Otherwise the next candidate fails with -EBUSY.

Handle power-on errors without attempting an ID read, and never continue
initializing the last candidate after all panel ID probes have failed.
Continuing after panel_slave_if_uinit() caused an access to the powered-off
DSI1 register block at 0x31400000 and a synchronous abort.

Also unwind GPIOs acquired by a partially failed power-on sequence and
check the selected init callback before invoking it.
---
 drivers/video/sprd/panel-if/panel_ops_mipi.c | 31 ++++++++++++++++++++++++----
 drivers/video/sprd/sprd_panel.c              | 38 +++++++++++++++++---------
 2 files changed, 52 insertions(+), 17 deletions(-)

--- a/drivers/video/sprd/panel-if/panel_ops_mipi.c
+++ b/drivers/video/sprd/panel-if/panel_ops_mipi.c
@@ -378,6 +378,10 @@
 	struct panel_info *info = &panel_device;
 	struct power_gpio *io = &info->power_pin;
 	int ret;
+	bool iovdd_requested = false;
+	bool avdd_requested = false;
+	bool avee_requested = false;
+	bool reset_requested = false;
 
 	if (!io->gpio_reset) {
 		pr_err("gpio_reset is NULL\n");
@@ -390,8 +394,9 @@
 						   &power_iovdd, GPIOD_IS_OUT);
 			if (ret) {
 				pr_err("request sprd,lcd-iovdd-gpio fail:%d\n", ret);
-				return ret;
+				goto power_on_failed;
 			}
+			iovdd_requested = true;
 			dm_gpio_set_value(&power_iovdd, 1);
 			mdelay(10);
 		}
@@ -401,8 +406,9 @@
 						   &power_avdd, GPIOD_IS_OUT);
 			if (ret) {
 				pr_err("request sprd,lcd-avdd-gpio fail:%d\n", ret);
-				return ret;
+				goto power_on_failed;
 			}
+			avdd_requested = true;
 			dm_gpio_set_value(&power_avdd, 1);
 			mdelay(info->power_gpio_delay);
 		}
@@ -412,8 +418,9 @@
 						   &power_avee, GPIOD_IS_OUT);
 			if (ret) {
 				pr_err("request sprd,lcd-avee-gpio fail:%d\n", ret);
-				return ret;
+				goto power_on_failed;
 			}
+			avee_requested = true;
 			dm_gpio_set_value(&power_avee, 1);
 			mdelay(20);
 		}
@@ -435,8 +442,9 @@
 						   &power_reset, GPIOD_IS_OUT);
 		if (ret) {
 			pr_err("request sprd,lcd-reset-gpio fail:%d\n", ret);
-			return ret;
+			goto power_on_failed;
 		}
+		reset_requested = true;
 
 		timing = info->power_on_seq.timing;
 		for (i = 0; i < info->power_on_seq.items; i++) {
@@ -463,10 +471,25 @@
 
 			dm_gpio_free(dev, &power_avdd);
 			dm_gpio_free(dev, &power_avee);
+			dm_gpio_free(dev, &power_iovdd);
 			dm_gpio_free(dev, &power_off);
 		}
 #endif
 	return 0;
+
+#ifndef CONFIG_FPGA
+power_on_failed:
+	if (reset_requested)
+		dm_gpio_free(dev, &power_reset);
+	if (avee_requested)
+		dm_gpio_free(dev, &power_avee);
+	if (avdd_requested)
+		dm_gpio_free(dev, &power_avdd);
+	if (iovdd_requested)
+		dm_gpio_free(dev, &power_iovdd);
+
+	return ret;
+#endif
 }
 
 static int panel_set_brightness(int level)
--- a/drivers/video/sprd/sprd_panel.c
+++ b/drivers/video/sprd/sprd_panel.c
@@ -821,12 +821,13 @@
 static int sprd_panel_probe(struct udevice *dev)
 {
 	struct panel_info *info;
-	struct sprd_panel_ops *ops;
+	struct sprd_panel_ops *ops = NULL;
 	u8 *info_addr;
 	int lcd_offset, offset;
 	int ret = -1;
 	int lcd_panel_offset = 0;
 	int info_size;
+	bool panel_powered;
 	struct udevice *panel_dev = NULL;
 	const void *fdt = gd->fdt_blob;
 
@@ -877,6 +878,7 @@
 
 	for (offset = fdt_first_subnode(fdt, lcd_offset);
 		offset >= 0; offset = fdt_next_subnode(fdt, offset)) {
+		panel_powered = false;
 		if (info) {
 			memset((uint8_t *)info_addr, 0, info_size);
 			of_parse_panel(fdt, offset, info);
@@ -890,7 +892,13 @@
 		ops = panel_drv->ops;
 		if (ops && ops->power) {
 			printf("enter power panel\n");
-			ops->power(dev, true);
+			ret = ops->power(dev, true);
+			if (ret) {
+				pr_err("power on panel 0x%x failed: %d\n",
+				       info->lcd_id, ret);
+				goto panel_probe_failed;
+			}
+			panel_powered = true;
 		}
 
 		if (ops && ops->read_id) {
@@ -903,7 +911,8 @@
 			}
 		}
 
-		if (ops && ops->power) {
+panel_probe_failed:
+		if (panel_powered && ops && ops->power) {
 			ops->power(dev, false);
 		}
 
@@ -919,7 +928,7 @@
 
 	if (ret) {
 		pr_err("No Panel Attached!\n");
-		//return -1;
+		return ret;
 	}
 
 	if (info->dual_dsi_en){
@@ -929,18 +938,21 @@
 			panel_if_init();
 	}
 
-	if (ops && ops->init){
-		if(info->mipi_port == 0){
+	if (info->mipi_port == 0) {
+		if (ops && ops->init)
 			ops->init();
-		}
-		else
+	} else {
+		if (ops && ops->slave_init)
 			ops->slave_init();
 	}
-	if (info->dual_dsi_en){
-		if(info->mipi_port == 0)
-			ops->slave_init();
-		else
-			ops->init();
+	if (info->dual_dsi_en) {
+		if (info->mipi_port == 0) {
+			if (ops && ops->slave_init)
+				ops->slave_init();
+		} else {
+			if (ops && ops->init)
+				ops->init();
+		}
 	}
 
 
-- 
2.34.1