我使用的计算机有 4 个不同的 PCI 插槽。我在其中一个插槽（x4 通道插槽）中使用 x4 通道 PCIe 设备，它工作正常。但是，我还没有设法让它在 x16 通道中工作。起初我以为操作系统无法识别该设备，但现在我认为这是 PCI 插槽本身的问题：当我使用 sudo dmidecode | grep "PCI" 时，它会列出所有 PCIe 插槽，但当我使用 sudo lspci | grep "PCI" 时，它只显示三个插槽中的三个，缺少 x16 插槽（见下面的输出）。我使用的是 CENTOS 7。有没有办法激活 x16 PCIe 插槽，这样我就可以像使用 x4 PCIe 插槽一样将它与我的设备一起使用？当我将设备连接到 x16 插槽时，它供电良好（LED 闪烁，就像连接到 x4 通道 PCIe 时一样）。
谢谢！
PS. 我尝试使用的设备是 PCIe 驱动的 FPGA
$sudo dmidecode | grep "PCI"
PCI is supported
Designation: Slot1 / X16PCIEXP
Type: x16 PCI Express 3 x16
Designation: Slot2 / X1PCIEXP1
Type: x1 PCI Express 2 x1
Designation: Slot3 / X1PCIEXP2
Type: x1 PCI Express 2 x1
Designation: Slot4 / X4PCIEXP
Type: x4 PCI Express 2 x4
HP BIOS iSCSI NIC PCI and MAC Information
NIC 1: PCI device 01:00.3, MAC address 00:02:01:00:00:00
NIC 2: PCI device 00:00.2, MAC address 00:00:00:BA:00:03
HP BIOS iSCSI NIC PCI and MAC Information
NIC 1: PCI device 01:00.3, MAC address 00:02:01:00:00:00
NIC 2: PCI device 00:00.2, MAC address 0B:00:00:05:00:03
HP BIOS iSCSI NIC PCI and MAC Information
NIC 1: PCI device 01:01.1, MAC address 00:02:01:00:00:00
NIC 2: PCI device 03:00.2, MAC address FF:FF:FF:FF:FF:04
NIC 3: PCI device ff:00.0, MAC address FF:FF:31:00:05:00
NIC 8: PCI device 0a:00.0, MAC address 00:34:00:00:00:00
HP BIOS iSCSI NIC PCI and MAC Information
NIC 1: PCI device 01:00.7, MAC address 00:02:01:00:00:00
NIC 2: PCI device 00:00.2, MAC address 02:01:00:00:00:03
NIC 3: PCI device 02:00.0, MAC address 01:00:00:00:04:05
NIC 6: PCI device 07:1f.7, MAC address 00:08:00:FF:FF:FF
$ sudo lspci | grep "PCI"
00:1c.0 PCI bridge: Intel Corporation Sunrise Point-H PCI Express Root Port #6 (rev f1)
00:1c.6 PCI bridge: Intel Corporation Sunrise Point-H PCI Express Root Port #7 (rev f1)
00:1d.0 PCI bridge: Intel Corporation Sunrise Point-H PCI Express Root Port #9 (rev f1)
编辑：更多命令的输出：
$ lspci -nm
00:00.0 "0600" "8086" "191f" -r07 "103c" "8053"
00:02.0 "0300" "8086" "1912" -r06 "103c" "8053"
00:14.0 "0c03" "8086" "a12f" -r31 -p30 "103c" "8053"
00:14.2 "1180" "8086" "a131" -r31 "103c" "8053"
00:16.0 "0780" "8086" "a13a" -r31 "103c" "8053"
00:16.3 "0700" "8086" "a13d" -r31 -p02 "103c" "8053"
00:17.0 "0106" "8086" "a102" -r31 -p01 "103c" "8053"
00:1c.0 "0604" "8086" "a115" -rf1 "" ""
00:1c.6 "0604" "8086" "a116" -rf1 "" ""
00:1d.0 "0604" "8086" "a118" -rf1 "" ""
00:1f.0 "0601" "8086" "a146" -r31 "103c" "8053"
00:1f.2 "0580" "8086" "a121" -r31 "103c" "8053"
00:1f.3 "0403" "8086" "a170" -r31 "103c" "8053"
00:1f.4 "0c05" "8086" "a123" -r31 "103c" "8053"
00:1f.6 "0200" "8086" "15b7" -r31 "103c" "8053"
$ lspci -t
-[0000:00]-+-00.0
+-02.0
+-14.0
+-14.2
+-16.0
+-16.3
+-17.0
+-1c.0-[01]--
+-1c.6-[02]--
+-1d.0-[03]--
+-1f.0
+-1f.2
+-1f.3
+-1f.4
\-1f.6
$ lspci -nn
00:00.0 Host bridge [0600]: Intel Corporation Skylake Host Bridge/DRAM Registers [8086:191f] (rev 07)
00:02.0 VGA compatible controller [0300]: Intel Corporation HD Graphics 530 [8086:1912] (rev 06)
00:14.0 USB controller [0c03]: Intel Corporation Sunrise Point-H USB 3.0 xHCI Controller [8086:a12f] (rev 31)
00:14.2 Signal processing controller [1180]: Intel Corporation Sunrise Point-H Thermal subsystem [8086:a131] (rev 31)
00:16.0 Communication controller [0780]: Intel Corporation Sunrise Point-H CSME HECI #1 [8086:a13a] (rev 31)
00:16.3 Serial controller [0700]: Intel Corporation Sunrise Point-H KT Redirection [8086:a13d] (rev 31)
00:17.0 SATA controller [0106]: Intel Corporation Sunrise Point-H SATA controller [AHCI mode] [8086:a102] (rev 31)
00:1c.0 PCI bridge [0604]: Intel Corporation Sunrise Point-H PCI Express Root Port #6 [8086:a115] (rev f1)
00:1c.6 PCI bridge [0604]: Intel Corporation Sunrise Point-H PCI Express Root Port #7 [8086:a116] (rev f1)
00:1d.0 PCI bridge [0604]: Intel Corporation Sunrise Point-H PCI Express Root Port #9 [8086:a118] (rev f1)
00:1f.0 ISA bridge [0601]: Intel Corporation Sunrise Point-H LPC Controller [8086:a146] (rev 31)
00:1f.2 Memory controller [0580]: Intel Corporation Sunrise Point-H PMC [8086:a121] (rev 31)
00:1f.3 Audio device [0403]: Intel Corporation Sunrise Point-H HD Audio [8086:a170] (rev 31)
00:1f.4 SMBus [0c05]: Intel Corporation Sunrise Point-H SMBus [8086:a123] (rev 31)
00:1f.6 Ethernet controller [0200]: Intel Corporation Ethernet Connection (2) I219-LM [8086:15b7] (rev 31)
03:00.0 Signal processing controller [1180]: Xilinx Corporation Device [10ee:7024]