From: Ansuel Smith <ansuelsmth@gmail.com>
Date: Tue, 1 Sep 2020 14:49:54 +0200
Subject: PCI: qcom: Make sure PCIe is reset before init for rev 2.1.0
Git-commit: d3d4d028afb785e52c55024d779089654f8302e7
Patch-mainline: 5.10-rc1
References: git-fixes

Qsdk U-Boot can incorrectly leave the PCIe interface in an undefined
state if bootm command is used instead of bootipq. This is caused by the
not deinit of PCIe when bootm is called. Reset the PCIe before init
anyway to fix this U-Boot bug.

Link: https://lore.kernel.org/r/20200901124955.137-1-ansuelsmth@gmail.com
Fixes: 82a823833f4e ("PCI: qcom: Add Qualcomm PCIe controller driver")
Signed-off-by: Ansuel Smith <ansuelsmth@gmail.com>
Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Reviewed-by: Bjorn Andersson <bjorn.andersson@linaro.org>
Cc: stable@vger.kernel.org # v4.19+
Signed-off-by: Jiri Slaby <jslaby@suse.cz>
---
 drivers/pci/dwc/pcie-qcom.c |   13 +++++++++++++
 1 file changed, 13 insertions(+)

--- a/drivers/pci/dwc/pcie-qcom.c
+++ b/drivers/pci/dwc/pcie-qcom.c
@@ -318,6 +318,9 @@ static void qcom_pcie_deinit_2_1_0(struc
 	clk_disable_unprepare(res->core_clk);
 	clk_disable_unprepare(res->aux_clk);
 	clk_disable_unprepare(res->ref_clk);
+
+	writel(1, pcie->parf + PCIE20_PARF_PHY_CTRL);
+
 	regulator_bulk_disable(ARRAY_SIZE(res->supplies), res->supplies);
 }
 
@@ -330,6 +333,16 @@ static int qcom_pcie_init_2_1_0(struct q
 	u32 val;
 	int ret;
 
+	/* reset the PCIe interface as uboot can leave it undefined state */
+	reset_control_assert(res->pci_reset);
+	reset_control_assert(res->axi_reset);
+	reset_control_assert(res->ahb_reset);
+	reset_control_assert(res->por_reset);
+	reset_control_assert(res->ext_reset);
+	reset_control_assert(res->phy_reset);
+
+	writel(1, pcie->parf + PCIE20_PARF_PHY_CTRL);
+
 	ret = regulator_bulk_enable(ARRAY_SIZE(res->supplies), res->supplies);
 	if (ret < 0) {
 		dev_err(dev, "cannot enable regulators\n");