From: Ansuel Smith ansuelsmth@gmail.com
[ Upstream commit d3d4d028afb785e52c55024d779089654f8302e7 ]
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: Sasha Levin sashal@kernel.org --- drivers/pci/controller/dwc/pcie-qcom.c | 13 +++++++++++++ 1 file changed, 13 insertions(+)
diff --git a/drivers/pci/controller/dwc/pcie-qcom.c b/drivers/pci/controller/dwc/pcie-qcom.c index 374db5d59cf87..14196c0287a24 100644 --- a/drivers/pci/controller/dwc/pcie-qcom.c +++ b/drivers/pci/controller/dwc/pcie-qcom.c @@ -303,6 +303,9 @@ static void qcom_pcie_deinit_2_1_0(struct qcom_pcie *pcie) 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); }
@@ -315,6 +318,16 @@ 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");