[PATCH v3 4/7] PCI: intel-gw: Enable clock before phy init

[Florian Eckert]

To ensure that the boot sequence is correct, the dwc pcie core clock must
be switched on before phy init call [1]. This changes are based on patched
kernel sources of the MaxLinear SDK.

[1] https://github.com/maxlinear/linux/blob/updk_9.1.90/drivers/pci/controller/dwc/pcie-intel-gw.c#L544

Signed-off-by: Florian Eckert <fe@xxxxxxxxxx>
---
 drivers/pci/controller/dwc/pcie-intel-gw.c | 19 ++++++++++---------
 1 file changed, 10 insertions(+), 9 deletions(-)

diff --git a/drivers/pci/controller/dwc/pcie-intel-gw.c b/drivers/pci/controller/dwc/pcie-intel-gw.c
index e88b8243cc41c607c39e4d58c4dcd8c8c082e8b0..6d9499d954674a26a74bff56b7fb5759767424c0 100644
--- a/drivers/pci/controller/dwc/pcie-intel-gw.c
+++ b/drivers/pci/controller/dwc/pcie-intel-gw.c
@@ -291,13 +291,9 @@ static int intel_pcie_host_setup(struct intel_pcie *pcie)
 
 	intel_pcie_core_rst_assert(pcie);
 	intel_pcie_device_rst_assert(pcie);
-
-	ret = phy_init(pcie->phy);
-	if (ret)
-		return ret;
-
 	intel_pcie_core_rst_deassert(pcie);
 
+	/* Controller clock must be provided earlier than PHY */
 	ret = clk_prepare_enable(pcie->core_clk);
 	if (ret) {
 		dev_err(pcie->pci.dev, "Core clock enable failed: %d\n", ret);
@@ -306,13 +302,17 @@ static int intel_pcie_host_setup(struct intel_pcie *pcie)
 
 	pci->atu_base = pci->dbi_base + 0xC0000;
 
+	ret = phy_init(pcie->phy);
+	if (ret)
+		goto phy_err;
+
 	intel_pcie_ltssm_disable(pcie);
 	intel_pcie_link_setup(pcie);
 	intel_pcie_init_n_fts(pci);
 
 	ret = dw_pcie_setup_rc(&pci->pp);
 	if (ret)
-		goto app_init_err;
+		goto err;
 
 	dw_pcie_upconfig_setup(pci);
 
@@ -321,17 +321,18 @@ static int intel_pcie_host_setup(struct intel_pcie *pcie)
 
 	ret = dw_pcie_wait_for_link(pci);
 	if (ret)
-		goto app_init_err;
+		goto err;
 
 	intel_pcie_core_irq_enable(pcie);
 
 	return 0;
 
-app_init_err:
+err:
+	phy_exit(pcie->phy);
+phy_err:
 	clk_disable_unprepare(pcie->core_clk);
 clk_err:
 	intel_pcie_core_rst_assert(pcie);
-	phy_exit(pcie->phy);
 
 	return ret;
 }

-- 
2.47.3