[PATCH v5 14/17] mtd: spinand: extract variant ranking logic into spinand_op_find_best_variant()

[Santhosh Kumar K <s-k6@ti.com>]

Refactor spinand_select_op_variant() to extract the inner loop into a
shared helper spinand_op_find_best_variant(). The helper takes a
skip_mask bitmask of already-tried variant indices, enabling callers to
iterate variants in ranked performance order while skipping those
already attempted. spinand_select_op_variant() becomes a one-liner
wrapper. No functional change.

Signed-off-by: Santhosh Kumar K <s-k6@ti.com>
---
 drivers/mtd/nand/spi/core.c | 32 +++++++++++++++++++++++++++-----
 1 file changed, 27 insertions(+), 5 deletions(-)

diff --git a/drivers/mtd/nand/spi/core.c b/drivers/mtd/nand/spi/core.c
index 8bf9301f25e7..7c3341f1fca0 100644
--- a/drivers/mtd/nand/spi/core.c
+++ b/drivers/mtd/nand/spi/core.c
@@ -1542,9 +1542,22 @@ static int spinand_init_odtr_instruction_set(struct spinand_device *spinand)
 	return 0;
 }
 
+/*
+ * spinand_op_find_best_variant() - Find the fastest eligible op variant.
+ * @spinand:    SPI NAND device
+ * @variants:   full variant list to search
+ * @iface:      bus interface to consider (ODTR or SSDR)
+ * @skip_mask:  bitmask of variant indices to skip (already tried)
+ *
+ * Iterates @variants, evaluates transfer duration for each eligible op, and
+ * returns a pointer to the fastest one not in @skip_mask.  Returns NULL when
+ * no eligible variant remains.  Used by both variant selection at init time
+ * (skip_mask == 0) and ranked PHY tuning iteration.
+ */
 static const struct spi_mem_op *
-spinand_select_op_variant(struct spinand_device *spinand, enum spinand_bus_interface iface,
-			  const struct spinand_op_variants *variants)
+spinand_op_find_best_variant(struct spinand_device *spinand,
+			     const struct spinand_op_variants *variants,
+			     enum spinand_bus_interface iface, u32 skip_mask)
 {
 	struct nand_device *nand = spinand_to_nand(spinand);
 	const struct spi_mem_op *best_variant = NULL;
@@ -1552,15 +1565,16 @@ spinand_select_op_variant(struct spinand_device *spinand, enum spinand_bus_inter
 	unsigned int i;
 
 	for (i = 0; i < variants->nops; i++) {
-		struct spi_mem_op op = variants->ops[i];
+		struct spi_mem_op op;
 		u64 op_duration_ns = 0;
 		unsigned int nbytes;
 		int ret;
 
-		if ((iface == SSDR && spinand_op_is_odtr(&op)) ||
-		    (iface == ODTR && !spinand_op_is_odtr(&op)))
+		if ((skip_mask & BIT(i)) ||
+		    spinand_op_is_odtr(&variants->ops[i]) != (iface == ODTR))
 			continue;
 
+		op = variants->ops[i];
 		nbytes = nanddev_per_page_oobsize(nand) +
 			 nanddev_page_size(nand);
 
@@ -1589,6 +1603,14 @@ spinand_select_op_variant(struct spinand_device *spinand, enum spinand_bus_inter
 	return best_variant;
 }
 
+static const struct spi_mem_op *
+spinand_select_op_variant(struct spinand_device *spinand,
+			  enum spinand_bus_interface iface,
+			  const struct spinand_op_variants *variants)
+{
+	return spinand_op_find_best_variant(spinand, variants, iface, 0);
+}
+
 /**
  * spinand_match_and_init() - Try to find a match between a device ID and an
  *			      entry in a spinand_info table
-- 
2.34.1