[openwrt/openwrt] ipq806x: fix pci broken on bootm command

[LEDE Commits]

adrian pushed a commit to openwrt/openwrt.git, branch master:
https://git.openwrt.org/f47cb405cafd57a25fceb7630af969e08b2f671c

commit f47cb405cafd57a25fceb7630af969e08b2f671c
Author: Ansuel Smith <ansuelsmth at gmail.com>
AuthorDate: Tue Sep 1 14:59:37 2020 +0200

    ipq806x: fix pci broken on bootm command
    
    Pci is broken when bootm is used instead of the custom bootipq. This
    is caused by the lack of reset by the bootloader. Make the driver do
    the reset to fix this specific problem.
    
    Signed-off-by: Ansuel Smith <ansuelsmth at gmail.com>
---
 ...ke-sure-PCIe-is-reset-before-init-for-rev.patch | 51 ++++++++++++++++++++++
 1 file changed, 51 insertions(+)

diff --git a/target/linux/ipq806x/patches-5.4/096-PCI-qcom-Make-sure-PCIe-is-reset-before-init-for-rev.patch b/target/linux/ipq806x/patches-5.4/096-PCI-qcom-Make-sure-PCIe-is-reset-before-init-for-rev.patch
new file mode 100644
index 0000000000..5c93d3199a
--- /dev/null
+++ b/target/linux/ipq806x/patches-5.4/096-PCI-qcom-Make-sure-PCIe-is-reset-before-init-for-rev.patch
@@ -0,0 +1,51 @@
+From 1960d75e3251659be8276529e4d01cf6993d9f4a Mon Sep 17 00:00:00 2001
+From: Ansuel Smith <ansuelsmth at gmail.com>
+Date: Tue, 1 Sep 2020 14:21:44 +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.
+
+Signed-off-by: Ansuel Smith <ansuelsmth at gmail.com>
+Fixes: 82a823833f4e ("PCI: qcom: Add Qualcomm PCIe controller driver")
+Cc: stable at vger.kernel.org # v4.19+
+---
+ 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 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");
+-- 
+2.27.0
+