The patch below does not apply to the 5.4-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to stable@vger.kernel.org.
thanks,
greg k-h
------------------ original commit in Linus's tree ------------------
From d3d4d028afb785e52c55024d779089654f8302e7 Mon Sep 17 00:00:00 2001
From: Ansuel Smith ansuelsmth@gmail.com Date: Tue, 1 Sep 2020 14:49:54 +0200 Subject: [PATCH] PCI: qcom: Make sure PCIe is reset before init for rev 2.1.0
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+
diff --git a/drivers/pci/controller/dwc/pcie-qcom.c b/drivers/pci/controller/dwc/pcie-qcom.c index 3aac77a295ba..82336bbaf8dc 100644 --- a/drivers/pci/controller/dwc/pcie-qcom.c +++ b/drivers/pci/controller/dwc/pcie-qcom.c @@ -302,6 +302,9 @@ static void qcom_pcie_deinit_2_1_0(struct qcom_pcie *pcie) 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); + regulator_bulk_disable(ARRAY_SIZE(res->supplies), res->supplies); }
@@ -314,6 +317,16 @@ static int qcom_pcie_init_2_1_0(struct qcom_pcie *pcie) 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");