[PATCH v2] clk: mediatek: fix using clocks before relocation

Remove the static mtk_clk_providers array. Static variables cannot be
used before relocation in U-Boot, so it broke systems that used clocks
before relocation, e.g. for UART early console.

The mtk_clk_providers array was likely premature optimization anyway
since it only saves a few cycles of searching a small number of clock
devices on each parent lookup.

Reported-by: Sam Shih <[email protected]>
Fixes: 8ef0ad4c7a6d ("clk: mediatek: use registered provider for parent lookup")
Signed-off-by: David Lechner <[email protected]>
---
Changes in v2:
- Change patch subject.
- Remove mtk_clk_providers array instead of clearing it.
- Link to v1: https://patch.msgid.link/20260813-mtk-clk-fix-reprobe-regression-v1-1-ed259968c2b8@baylibre.com
---
 drivers/clk/mediatek/clk-mtk.c | 70 +++++++++++++++---------------------------
 1 file changed, 25 insertions(+), 45 deletions(-)

diff --git a/drivers/clk/mediatek/clk-mtk.c b/drivers/clk/mediatek/clk-mtk.c
index 13c248c93a6..70cc7624a14 100644
--- a/drivers/clk/mediatek/clk-mtk.c
+++ b/drivers/clk/mediatek/clk-mtk.c
@@ -35,8 +35,6 @@
 #define SCP_AXICK_DCM_DIS_EN		BIT(0)
 #define SCP_AXICK_26M_SEL_EN		BIT(4)
 
-static struct udevice *mtk_clk_providers[MTK_CLK_TREE_NUM_TYPES];
-
 static bool mtk_clk_tree_type_is_provider(enum mtk_clk_tree_type type)
 {
 	return type != MTK_CLK_TREE_NONE && type < MTK_CLK_TREE_NUM_TYPES;
@@ -58,44 +56,40 @@ static enum mtk_clk_tree_type mtk_clk_tree_type_from_parent_flags(u16 flags)
 
 static struct udevice *mtk_clk_tree_get_provider(enum mtk_clk_tree_type type)
 {
+	struct udevice *dev;
+	struct uclass *uc;
+	int ret;
+
 	if (!mtk_clk_tree_type_is_provider(type))
 		return NULL;
 
-	if (!mtk_clk_providers[type]) {
-		struct udevice *dev;
-		struct uclass *uc;
-		int ret;
-
-		/* Lazily probe and register the requested provider. */
-		ret = uclass_get(UCLASS_CLK, &uc);
-		if (ret)
-			return ERR_PTR(ret);
+	ret = uclass_get(UCLASS_CLK, &uc);
+	if (ret)
+		return ERR_PTR(ret);
 
-		uclass_foreach_dev(dev, uc) {
-			const struct mtk_clk_tree *tree;
-			const void *ops;
+	uclass_foreach_dev(dev, uc) {
+		const struct mtk_clk_tree *tree;
+		const void *ops;
 
-			ops = dev_get_driver_ops(dev);
-			if (ops != &mtk_clk_apmixedsys_ops &&
-			    ops != &mtk_clk_fixed_pll_ops &&
-			    ops != &mtk_clk_topckgen_ops &&
-			    ops != &mtk_clk_infrasys_ops)
-				continue;
+		ops = dev_get_driver_ops(dev);
+		if (ops != &mtk_clk_apmixedsys_ops &&
+		    ops != &mtk_clk_fixed_pll_ops &&
+		    ops != &mtk_clk_topckgen_ops &&
+		    ops != &mtk_clk_infrasys_ops)
+			continue;
 
-			tree = (const void *)dev_get_driver_data(dev);
-			if (tree->type != type)
-				continue;
+		tree = (const void *)dev_get_driver_data(dev);
+		if (tree->type != type)
+			continue;
 
-			/* Probe will add it to mtk_clk_providers[type]. */
-			ret = device_probe(dev);
-			if (ret)
-				return ERR_PTR(ret);
+		ret = device_probe(dev);
+		if (ret)
+			return ERR_PTR(ret);
 
-			break;
-		}
+		return dev;
 	}
 
-	return mtk_clk_providers[type] ?: ERR_PTR(-ENOENT);
+	return ERR_PTR(-ENOENT);
 }
 
 static struct udevice *mtk_clk_parent_get_provider(u16 flags)
@@ -103,20 +97,6 @@ static struct udevice *mtk_clk_parent_get_provider(u16 flags)
 	return mtk_clk_tree_get_provider(mtk_clk_tree_type_from_parent_flags(flags));
 }
 
-static int mtk_clk_tree_register_provider(struct udevice *dev,
-					  const struct mtk_clk_tree *tree)
-{
-	if (!mtk_clk_tree_type_is_provider(tree->type))
-		return 0;
-
-	if (mtk_clk_providers[tree->type])
-		return -EEXIST;
-
-	mtk_clk_providers[tree->type] = dev;
-
-	return 0;
-}
-
 /* shared functions */
 
 static const int mtk_common_clk_of_xlate(struct clk *clk,
@@ -1128,5 +1108,5 @@ int mtk_clk_probe(struct udevice *dev)
 
 	priv->tree = tree;
 
-	return mtk_clk_tree_register_provider(dev, tree);
+	return 0;
 }

---
base-commit: 0b581a9612e46310ee52bf8359165950d38b2a2b
change-id: 20260813-mtk-clk-fix-reprobe-regression-6ac0c072600b

Best regards,
--  
David Lechner <[email protected]>