PCIe Development and Testing

T527 quick validation

dmesg | grep -Ei 'pcie|combophy|link'
lspci
lspci -vv

T527 is expected to expose PCIe 2.1 RC x1. lspci should show the root bridge and then the downstream endpoint. If only the bridge appears, inspect PERST#, REFCLK, supplies, and link training.

NVMe SSD

ls /dev/nvme*
nvme list
fdisk -l /dev/nvme0n1

Enable the NVMe block driver. The supply must handle SSD startup current; an undersized rail causes repeated enumeration or I/O errors.

PCIe Ethernet

Identify the endpoint VID/PID and enable its driver; Realtek devices commonly use r8169. If enumeration succeeds but no network interface appears, inspect the endpoint driver and firmware requirements.

IDs and modes

The RC/EP compatible and driver version must match. The T527 scope is RC; do not copy DM-mode configuration from MR536, T536, or A733 without checking the hardware and driver.

Common build and flash workflow

cd <ANDROID_TOP>/longan
./build.sh kernel
./build.sh pack

After flashing, confirm the kernel/DTB build timestamp and version so that new changes are not evaluated on an old image.