diff --git a/drivers/tty/serial/8250/8250_pci.c b/drivers/tty/serial/8250/8250_pci.c
index dd48b910bb05..d22f727491b5 100644
--- a/drivers/tty/serial/8250/8250_pci.c
+++ b/drivers/tty/serial/8250/8250_pci.c
@@ -83,14 +83,20 @@
 
 #define PCI_DEVICE_ID_MOXA_CP102E	0x1024
 #define PCI_DEVICE_ID_MOXA_CP102EL	0x1025
+#define PCI_DEVICE_ID_MOXA_CP102N	0x1027
 #define PCI_DEVICE_ID_MOXA_CP104EL_A	0x1045
+#define PCI_DEVICE_ID_MOXA_CP104N	0x1046
+#define PCI_DEVICE_ID_MOXA_CP112N	0x1121
 #define PCI_DEVICE_ID_MOXA_CP114EL	0x1144
+#define PCI_DEVICE_ID_MOXA_CP114N	0x1145
 #define PCI_DEVICE_ID_MOXA_CP116E_A_A	0x1160
 #define PCI_DEVICE_ID_MOXA_CP116E_A_B	0x1161
 #define PCI_DEVICE_ID_MOXA_CP118EL_A	0x1182
 #define PCI_DEVICE_ID_MOXA_CP118E_A_I	0x1183
 #define PCI_DEVICE_ID_MOXA_CP132EL	0x1322
+#define PCI_DEVICE_ID_MOXA_CP132N	0x1323
 #define PCI_DEVICE_ID_MOXA_CP134EL_A	0x1342
+#define PCI_DEVICE_ID_MOXA_CP134N	0x1343
 #define PCI_DEVICE_ID_MOXA_CP138E_A	0x1381
 #define PCI_DEVICE_ID_MOXA_CP168EL_A	0x1683
 
@@ -1959,6 +1965,49 @@ pci_sunix_setup(struct serial_private *priv,
 	return setup_port(priv, port, bar, offset, 0);
 }
 
+#define MOXA_PUART_GPIO_EN	0x09
+#define MOXA_PUART_GPIO_OUT	0x0A
+
+#define MOXA_GPIO_PIN2	BIT(2)
+
+static bool pci_moxa_is_mini_pcie(unsigned short device)
+{
+	if (device == PCI_DEVICE_ID_MOXA_CP102N	||
+	    device == PCI_DEVICE_ID_MOXA_CP104N	||
+	    device == PCI_DEVICE_ID_MOXA_CP112N	||
+	    device == PCI_DEVICE_ID_MOXA_CP114N ||
+	    device == PCI_DEVICE_ID_MOXA_CP132N ||
+	    device == PCI_DEVICE_ID_MOXA_CP134N)
+		return true;
+
+	return false;
+}
+
+static int pci_moxa_init(struct pci_dev *dev)
+{
+	unsigned short device = dev->device;
+	resource_size_t iobar_addr = pci_resource_start(dev, 2);
+	unsigned int num_ports = (device & 0x00F0) >> 4;
+	u8 val;
+
+	/*
+	 * Enable hardware buffer to prevent break signal output when system boots up.
+	 * This hardware buffer is only supported on Mini PCIe series.
+	 */
+	if (pci_moxa_is_mini_pcie(device)) {
+		/* Set GPIO direction */
+		val = inb(iobar_addr + MOXA_PUART_GPIO_EN);
+		val |= MOXA_GPIO_PIN2;
+		outb(val, iobar_addr + MOXA_PUART_GPIO_EN);
+		/* Enable low GPIO */
+		val = inb(iobar_addr + MOXA_PUART_GPIO_OUT);
+		val &= ~MOXA_GPIO_PIN2;
+		outb(val, iobar_addr + MOXA_PUART_GPIO_OUT);
+	}
+
+	return num_ports;
+}
+
 static int
 pci_moxa_setup(struct serial_private *priv,
 		const struct pciserial_board *board,
@@ -2635,6 +2684,7 @@ static struct pci_serial_quirk pci_serial_quirks[] = {
 		.device		= PCI_ANY_ID,
 		.subvendor	= PCI_ANY_ID,
 		.subdevice	= PCI_ANY_ID,
+		.init		= pci_moxa_init,
 		.setup		= pci_moxa_setup,
 	},
 	{
@@ -5351,14 +5401,20 @@ static const struct pci_device_id serial_pci_tbl[] = {
 	 */
 	{ PCI_VDEVICE(MOXA, PCI_DEVICE_ID_MOXA_CP102E),	    pbn_moxa_2 },
 	{ PCI_VDEVICE(MOXA, PCI_DEVICE_ID_MOXA_CP102EL),    pbn_moxa_2 },
+	{ PCI_VDEVICE(MOXA, PCI_DEVICE_ID_MOXA_CP102N),	    pbn_moxa_2 },
 	{ PCI_VDEVICE(MOXA, PCI_DEVICE_ID_MOXA_CP104EL_A),  pbn_moxa_4 },
+	{ PCI_VDEVICE(MOXA, PCI_DEVICE_ID_MOXA_CP104N),	    pbn_moxa_4 },
+	{ PCI_VDEVICE(MOXA, PCI_DEVICE_ID_MOXA_CP112N),	    pbn_moxa_2 },
 	{ PCI_VDEVICE(MOXA, PCI_DEVICE_ID_MOXA_CP114EL),    pbn_moxa_4 },
+	{ PCI_VDEVICE(MOXA, PCI_DEVICE_ID_MOXA_CP114N),	    pbn_moxa_4 },
 	{ PCI_VDEVICE(MOXA, PCI_DEVICE_ID_MOXA_CP116E_A_A), pbn_moxa_8 },
 	{ PCI_VDEVICE(MOXA, PCI_DEVICE_ID_MOXA_CP116E_A_B), pbn_moxa_8 },
 	{ PCI_VDEVICE(MOXA, PCI_DEVICE_ID_MOXA_CP118EL_A),  pbn_moxa_8 },
 	{ PCI_VDEVICE(MOXA, PCI_DEVICE_ID_MOXA_CP118E_A_I), pbn_moxa_8 },
 	{ PCI_VDEVICE(MOXA, PCI_DEVICE_ID_MOXA_CP132EL),    pbn_moxa_2 },
+	{ PCI_VDEVICE(MOXA, PCI_DEVICE_ID_MOXA_CP132N),     pbn_moxa_2 },
 	{ PCI_VDEVICE(MOXA, PCI_DEVICE_ID_MOXA_CP134EL_A),  pbn_moxa_4 },
+	{ PCI_VDEVICE(MOXA, PCI_DEVICE_ID_MOXA_CP134N),	    pbn_moxa_4 },
 	{ PCI_VDEVICE(MOXA, PCI_DEVICE_ID_MOXA_CP138E_A),   pbn_moxa_8 },
 	{ PCI_VDEVICE(MOXA, PCI_DEVICE_ID_MOXA_CP168EL_A),  pbn_moxa_8 },