no PCIe link with some devices

Robotics & Edge Computing Jetson Systems Jetson AGX Xavier
11

Hi vidyas,

the changes you proposed indeed helped. Patch you posted is reversed though, so in reality it looks like that:

--- kernel/nvidia/drivers/pci/host/pcie-tegra-dw.c.orig 2018-09-29 06:32:13.000000000 +0200
+++ kernel/nvidia/drivers/pci/host/pcie-tegra-dw.c      2018-11-01 15:32:21.657577341 +0100
@@ -2682,8 +2682,8 @@
                                return gpio;
 
                        f = (flags & OF_GPIO_ACTIVE_LOW) ?
-                           (GPIOF_OUT_INIT_HIGH | GPIOF_ACTIVE_LOW) :
-                            GPIOF_OUT_INIT_LOW;
+                           (GPIOF_OUT_INIT_LOW | GPIOF_ACTIVE_LOW) :
+                            GPIOF_OUT_INIT_HIGH;
 
                        ret = devm_gpio_request_one(pcie->dev, gpio, f, NULL);
                        if (ret < 0) {
--- hardware/nvidia/platform/t19x/galen/kernel-dts/common/tegra194-p2888-0000-a00.dtsi.orig     2018-09-29 06:30:53.000000000 +0200
+++ hardware/nvidia/platform/t19x/galen/kernel-dts/common/tegra194-p2888-0000-a00.dtsi  2018-11-01 15:29:46.958631704 +0100
@@ -79,6 +79,17 @@
                };
        };
 
+       gpio@2200000 {
+               pcie-reg-enable {
+                       gpio-hog;
+                       gpios = <TEGRA194_MAIN_GPIO(Z, 2) GPIO_ACTIVE_HIGH
+                                TEGRA194_MAIN_GPIO(A, 1) GPIO_ACTIVE_LOW>;
+                       label = "pcie-3v3-reg", "pcie-12v-reg";
+                       output-high;
+                       status = "disabled";
+               };
+       };
+
        pcie@14180000 {
                status = "okay";
 
--- hardware/nvidia/platform/t19x/galen/kernel-dts/common/tegra194-p2888-p2822-pcie-plugin-manager.dtsi.orig    2018-11-01 15:30:38.908277659 +0100
+++ hardware/nvidia/platform/t19x/galen/kernel-dts/common/tegra194-p2888-p2822-pcie-plugin-manager.dtsi 2018-11-01 15:31:43.647836417 +0100
@@ -52,6 +52,14 @@
                                                >;
                                };
                        };
+                       override@2 {
+                               target = <&{/gpio@2200000}>;
+                               _overlay_ {
+                                       pcie-reg-enable {
+                                               status = "okay";
+                                       };
+                               };
+                       };
                };
 
                fragment-disable-uphy-rx-idle {

I hope these changes and some fix for make modules_prepare (e.g. https://devtalk.nvidia.com/default/topic/1042391/jetson-agx-xavier/is-it-possible-to-build-kernel-module-in-xavier-solved-/post/5288000/#5288000) will be integrated into next L4T release.