From 1abff6be59495c5de9672709e381481f305631d6 Mon Sep 17 00:00:00 2001
From: Myron Stowe <mstowe@redhat.com>
Date: Mon, 24 Mar 2025 20:53:26 -0600
Subject: [PATCH] PCI: mediatek-gen3: Add comment about initialization order in
mtk_pcie_en7581_power_up()
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JIRA: https://issues.redhat.com/browse/RHEL-83611
Upstream Status: 0c9d2d2ef0d916b490a9222ed20ff4616fca876d
commit 0c9d2d2ef0d916b490a9222ed20ff4616fca876d
Author: Lorenzo Bianconi <lorenzo@kernel.org>
Date: Wed Jan 8 10:50:42 2025 +0100
PCI: mediatek-gen3: Add comment about initialization order in mtk_pcie_en7581_power_up()
Add a comment in mtk_pcie_en7581_power_up() to clarify, unlike the other
MediaTek Gen3 controllers, the Airoha EN7581 requires PHY initialization
and power-on before PHY reset deassert.
Link: https://lore.kernel.org/r/20250108-pcie-en7581-fixes-v6-3-21ac939a3b9b@kernel.org
Signed-off-by: Lorenzo Bianconi <lorenzo@kernel.org>
Signed-off-by: Krzysztof Wilczyński <kwilczynski@kernel.org>
Reviewed-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
Reviewed-by: AngeloGioacchino Del Regno <angelogioacchino.delregno@collabora.com>
Signed-off-by: Myron Stowe <mstowe@redhat.com>
---
drivers/pci/controller/pcie-mediatek-gen3.c | 4 ++++
1 file changed, 4 insertions(+)
diff --git a/drivers/pci/controller/pcie-mediatek-gen3.c b/drivers/pci/controller/pcie-mediatek-gen3.c
index 4ce2b9d0dcd54..71df8817c1635 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");
--
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