diff --git a/drivers/pci/controller/pcie-mediatek-gen3.c b/drivers/pci/controller/pcie-mediatek-gen3.c
index 4ce2b9d0dcd54e44cb645603d81865d26b2c8f23..71df8817c1635b04b67233fb43abe2de7770b0f2 100644
--- a/drivers/pci/controller/pcie-mediatek-gen3.c
+++ b/drivers/pci/controller/pcie-mediatek-gen3.c
@@ -925,6 +925,10 @@ static int mtk_pcie_en7581_power_up(struct mtk_gen3_pcie *pcie)
 	/* Wait for the time needed to complete the reset lines assert. */
 	mdelay(PCIE_EN7581_RESET_TIME_MS);
 
+	/*
+	 * Unlike the other MediaTek Gen3 controllers, the Airoha EN7581
+	 * requires PHY initialization and power-on before PHY reset deassert.
+	 */
 	err = phy_init(pcie->phy);
 	if (err) {
 		dev_err(dev, "failed to initialize PHY\n");