diff --git a/drivers/serial/8250.c b/drivers/serial/8250.c
index 5261f0af8b101bcf4e1149caebdb484bbe92aa70..2964ca9df5a010f9cebb264e4115d5a588e5c234 100644
--- a/drivers/serial/8250.c
+++ b/drivers/serial/8250.c
@@ -920,12 +920,16 @@ static void autoconfig(struct uart_8250_port *up, unsigned int probeflags)
 #ifdef __i386__
 		outb(0xff, 0x080);
 #endif
-		scratch2 = serial_inp(up, UART_IER);
+		/*
+		 * Mask out IER[7:4] bits for test as some UARTs (e.g. TL
+		 * 16C754B) allow only to modify them if an EFR bit is set.
+		 */
+		scratch2 = serial_inp(up, UART_IER) & 0x0f;
 		serial_outp(up, UART_IER, 0x0F);
 #ifdef __i386__
 		outb(0, 0x080);
 #endif
-		scratch3 = serial_inp(up, UART_IER);
+		scratch3 = serial_inp(up, UART_IER) & 0x0f;
 		serial_outp(up, UART_IER, scratch);
 		if (scratch2 != 0 || scratch3 != 0x0F) {
 			/*
diff --git a/drivers/serial/8250_pci.c b/drivers/serial/8250_pci.c
index 52e2e64c6649dc25379994f6b1b119bc2d3b768f..5dfaa0926cfd9b33abf09d2ce5227edef85383e5 100644
--- a/drivers/serial/8250_pci.c
+++ b/drivers/serial/8250_pci.c
@@ -677,6 +677,13 @@ static struct pci_serial_quirk pci_serial_quirks[] = {
 	/*
 	 * PLX
 	 */
+	{
+		.vendor		= PCI_VENDOR_ID_PLX,
+		.device		= PCI_DEVICE_ID_PLX_9030,
+		.subvendor	= PCI_SUBVENDOR_ID_PERLE,
+		.subdevice	= PCI_ANY_ID,
+		.setup		= pci_default_setup,
+	},
 	{
 		.vendor		= PCI_VENDOR_ID_PLX,
 		.device		= PCI_DEVICE_ID_PLX_9050,
@@ -2378,6 +2385,15 @@ static struct pci_device_id serial_pci_tbl[] = {
 		PCI_ANY_ID, PCI_ANY_ID, 0, 0,	/* 135a.0811 */
 		pbn_b2_2_115200 },
 
+	/*
+	 * Perle PCI-RAS cards
+	 */
+	{       PCI_VENDOR_ID_PLX, PCI_DEVICE_ID_PLX_9030,
+		PCI_SUBVENDOR_ID_PERLE, PCI_SUBDEVICE_ID_PCI_RAS4,
+		0, 0, pbn_b2_4_921600 },
+	{       PCI_VENDOR_ID_PLX, PCI_DEVICE_ID_PLX_9030,
+		PCI_SUBVENDOR_ID_PERLE, PCI_SUBDEVICE_ID_PCI_RAS8,
+		0, 0, pbn_b2_8_921600 },
 	/*
 	 * These entries match devices with class COMMUNICATION_SERIAL,
 	 * COMMUNICATION_MODEM or COMMUNICATION_MULTISERIAL
diff --git a/include/linux/pci_ids.h b/include/linux/pci_ids.h
index e5e5b9ffcfb518f8e4e07c7359e9762beeb18745..d655378f1c6326e67b88cc55c072ffde39b5a207 100644
--- a/include/linux/pci_ids.h
+++ b/include/linux/pci_ids.h
@@ -959,6 +959,7 @@
 #define PCI_DEVICE_ID_PLX_R753		0x1152
 #define PCI_DEVICE_ID_PLX_OLITEC	0x1187
 #define PCI_DEVICE_ID_PLX_PCI200SYN	0x3196
+#define PCI_DEVICE_ID_PLX_9030          0x9030
 #define PCI_DEVICE_ID_PLX_9050		0x9050
 #define PCI_DEVICE_ID_PLX_9080		0x9080
 #define PCI_DEVICE_ID_PLX_GTEK_SERIAL2	0xa001
@@ -1994,6 +1995,10 @@
 
 #define PCI_VENDOR_ID_CHELSIO		0x1425
 
+#define PCI_SUBVENDOR_ID_PERLE          0x155f
+#define PCI_SUBDEVICE_ID_PCI_RAS4       0xf001
+#define PCI_SUBDEVICE_ID_PCI_RAS8       0xf010
+
 
 #define PCI_VENDOR_ID_SYBA		0x1592
 #define PCI_DEVICE_ID_SYBA_2P_EPP	0x0782