1 files changed, 17 insertions, 0 deletions

diff --git a/drivers/serial/8250_pci.c b/drivers/serial/8250_pci.c
index fd76542c5977..e3140e5b16cc 100644
--- a/drivers/serial/8250_pci.c
+++ b/drivers/serial/8250_pci.c
@@ -1652,6 +1652,10 @@ static struct pciserial_board pci_boards[] __devinitdata = {
         },
 };
 
+static const struct pci_device_id softmodem_blacklist[] = {
+        { PCI_VDEVICE ( AL, 0x5457 ), }, /* ALi Corporation M5457 AC'97 Modem */
+};
+
 /*
  * Given a complete unknown PCI device, try to use some heuristics to
  * guess what the configuration might be, based on the pitiful PCI
@@ -1660,6 +1664,7 @@ static struct pciserial_board pci_boards[] __devinitdata = {
 static int __devinit
 serial_pci_guess_board(struct pci_dev *dev, struct pciserial_board *board)
 {
+        const struct pci_device_id *blacklist;
         int num_iomem, num_port, first_port = -1, i;
         
         /*
@@ -1674,6 +1679,18 @@ serial_pci_guess_board(struct pci_dev *dev, struct pciserial_board *board)
             (dev->class & 0xff) > 6)
                 return -ENODEV;
 
+        /*
+         * Do not access blacklisted devices that are known not to
+         * feature serial ports.
+         */
+        for (blacklist = softmodem_blacklist;
+             blacklist < softmodem_blacklist + ARRAY_SIZE(softmodem_blacklist);
+             blacklist++) {
+                if (dev->vendor == blacklist->vendor &&
+                    dev->device == blacklist->device)
+                        return -ENODEV;
+        }
+
         num_iomem = num_port = 0;
         for (i = 0; i < PCI_NUM_BAR_RESOURCES; i++) {
                 if (pci_resource_flags(dev, i) & IORESOURCE_IO) {