RK3576 Rock 4D: PCIe NVMe device not detected in mainline kernel despite working in U-Boot

[Nicolas Frattaroli]

On Wednesday, 24 December 2025 14:29:20 Central European Standard Time Leonard Lausen wrote:
> Hi linux-rockchip, Hi Nicolas,
> 
> I'm testing mainline kernel support on the Rock 4D board and 
> encountering an issue where PCIe NVMe devices are not detected by the 
> kernel, despite working correctly in U-Boot. That is despite Nicolas 
> recently enabling PCIe support for Rock 4D in 
> 29ff4bbff793334d6aff2238fdc3ccf3859d60da.
> 
> U-Boot successfully detects and initializes the NVMe device:
> 
> pcie at 2a200000: PCIe Linking... LTSSM is 0x0
> pcie at 2a200000: PCIe Link up, LTSSM is 0x130011
> pcie at 2a200000: PCIE-0: Link up (Gen2-x1, Bus0)
> 
> Device 0: Vendor: 0x1344 Rev: HPS0050  Prod: UTFRQ0170J8QSZ
>              Type: Hard Disk
>              Capacity: 488386.3 MB = 476.9 GB (1000215216 x 512)
> 
> 
> However, after kernel boot, only the PCIe root port is visible:
> 
> 00:00.0 PCI bridge: Device 1d87:3576 (rev 01)
> 
> 
> PCIe rescan debug output:
> 
> (initramfs) echo 1 > /sys/bus/pci/rescan
> [  106.782392] pci_bus 0000:00: scanning bus
> [  106.796249] pcieport 0000:00:00.0: restore config 0x2c: 0x00000000 -> 
> 0x00000000
> [  106.797060] pcieport 0000:00:00.0: restore config 0x28: 0x00000000 -> 
> 0x00000000
> [  106.797808] pcieport 0000:00:00.0: restore config 0x24: 0x0001fff1 -> 
> 0x0001fff1
> [  106.798583] pcieport 0000:00:00.0: PME# disabled
> [  106.799069] pcieport 0000:00:00.0: scanning [bus 01-ff] behind 
> bridge, pass 0
> [  106.799795] pci_bus 0000:01: scanning bus
> [  106.803471] pci_bus 0000:01: bus scan returning with max=01
> [  106.804073] pcieport 0000:00:00.0: scanning [bus 01-ff] behind 
> bridge, pass 1
> [  106.804829] pci_bus 0000:00: bus scan returning with max=ff
> (initramfs) [  106.924154] pcieport 0000:00:00.0: save config 0x00: 
> 0x35761d87
> [  106.924765] pcieport 0000:00:00.0: save config 0x04: 0x00100507
> [  106.925364] pcieport 0000:00:00.0: save config 0x08: 0x06040001
> [  106.925958] pcieport 0000:00:00.0: save config 0x0c: 0x00010000
> [  106.926534] pcieport 0000:00:00.0: save config 0x10: 0x00000000
> [  106.932142] pcieport 0000:00:00.0: save config 0x14: 0x00000000
> [  106.934608] pcieport 0000:00:00.0: save config 0x18: 0x00ff0100
> [  106.937206] pcieport 0000:00:00.0: save config 0x1c: 0x000000f0
> [  106.939575] pcieport 0000:00:00.0: save config 0x20: 0x0000fff0
> [  106.941883] pcieport 0000:00:00.0: save config 0x24: 0x0001fff1
> [  106.944138] pcieport 0000:00:00.0: save config 0x28: 0x00000000
> [  106.946335] pcieport 0000:00:00.0: save config 0x2c: 0x00000000
> [  106.948490] pcieport 0000:00:00.0: save config 0x30: 0x00000000
> [  106.950601] pcieport 0000:00:00.0: save config 0x34: 0x00000040
> [  106.952698] pcieport 0000:00:00.0: save config 0x38: 0x00000000
> [  106.954765] pcieport 0000:00:00.0: save config 0x3c: 0x0002012d
> [  106.956847] pcieport 0000:00:00.0: PME# enabled
> ls /sys/bus/pci/devices/
> drwxr-xr-x 2 0 0 0 .
> drwxr-xr-x 5 0 0 0 ..
> lrwxrwxrwx 1 0 0 0 0000:00:00.0 -> 
> ../../../devices/platform/soc/22000000.pcie/pci0000:00/0000:00:00.0
> 
> The full boot log including the u-boot part and kernel PCI_DEBUG output 
> is also attached.
> 
> Thanks for any insights!

Hi Leonard,

please try the following:

---
diff --git a/arch/arm64/boot/dts/rockchip/rk3576-rock-4d.dts b/arch/arm64/boot/dts/rockchip/rk3576-rock-4d.dts
index 7023dc326d0e..987e127cae1e 100644
--- a/arch/arm64/boot/dts/rockchip/rk3576-rock-4d.dts
+++ b/arch/arm64/boot/dts/rockchip/rk3576-rock-4d.dts
@@ -700,7 +700,7 @@ rgmii_phy0: ethernet-phy at 1 {
 &pcie0 {
        pinctrl-names = "default";
        pinctrl-0 = <&pcie_reset>;
-       reset-gpios = <&gpio2 RK_PB4 GPIO_ACTIVE_HIGH>;
+       reset-gpios = <&gpio2 RK_PB4 GPIO_ACTIVE_LOW>;
        vpcie3v3-supply = <&vcc_3v3_pcie>;
        status = "okay";
 };

---

>From my reading of the schematic, we messed up the reset GPIO
polarity here, so PCIe devices never get reset. Oopsie.

Kind regards,
Nicolas Frattaroli

> Best regards,
> Leonard
>