PCIe

CONFIG_HOTPLUG_PCI=y
CONFIG_PCI_HOST_GENERIC=y
CONFIG_PCIE_DW_PLAT_HOST=y
CONFIG_PCIE_QCOM=y
CONFIG_PCI_ENDPOINT=y
CONFIG_PCIEASPM=y
CONFIG_PCIEASPM_POWER_SUPERSAVE=y
CONFIG_BLK_DEV_NVME=y
CONFIG_NVME_CORE=y

lspci

0001:00:00.0 PCI bridge: Qualcomm Device 010b
0001:01:00.0 PCI bridge: Toshiba Corporation Device 0623
0001:05:00.0 Ethernet controller: Toshiba Corporation Device 0220

lspci -vv | grep -i "lnk"
cat /sys/bus/pci/devices/*/current_link_speed
cat /sys/bus/pci/devices/*/current_link_width

lspci
# Expected: USB controller: NEC Corporation uPD720200 USB 3.0 Host Controller

lsusb
# Shows connected USB devices

lspci | grep -i nvme
ls /dev/nvme*
nvme list

sudo su
echo 8 > /proc/sys/kernel/printk
echo "file pcie-qcom.c +p" > /sys/kernel/debug/dynamic_debug/control
echo "file pcie-designware-host.c +p" > /sys/kernel/debug/dynamic_debug/control

dmesg | grep -i pcie

lspci                                              # List all PCIe devices
lspci -vv                                          # Detailed device info
lspci -tv                                          # Tree view
lspci -nn                                          # With numeric IDs
dmesg | grep -i pcie                               # Kernel messages
cat /sys/bus/pci/devices/*/current_link_speed      # Link speeds
cat /sys/bus/pci/devices/*/current_link_width      # Link widths