diff --git a/drivers/spi/spi-npcm-fiu.c b/drivers/spi/spi-npcm-fiu.c
index ba67dbed9fb8f..d5b4fe7b9b621 100644
--- a/drivers/spi/spi-npcm-fiu.c
+++ b/drivers/spi/spi-npcm-fiu.c
@@ -252,8 +252,7 @@ static void npcm_fiu_set_drd(struct npcm_fiu_spi *fiu,
 	fiu->drd_op.addr.buswidth = op->addr.buswidth;
 	regmap_update_bits(fiu->regmap, NPCM_FIU_DRD_CFG,
 			   NPCM_FIU_DRD_CFG_DBW,
-			   ((op->dummy.nbytes * ilog2(op->addr.buswidth)) / BITS_PER_BYTE)
-			   << NPCM_FIU_DRD_DBW_SHIFT);
+			   op->dummy.nbytes << NPCM_FIU_DRD_DBW_SHIFT);
 	fiu->drd_op.dummy.nbytes = op->dummy.nbytes;
 	regmap_update_bits(fiu->regmap, NPCM_FIU_DRD_CFG,
 			   NPCM_FIU_DRD_CFG_RDCMD, op->cmd.opcode);