serial: 8250_pci: Don't fail on multiport card class

Do not fail on multiport cards in serial_pci_is_class_communication().

It restores behaviour for SUNIX multiport cards, that enumerated by
class and have a custom board data.

Moreover it allows users to reenumerate port-by-port from user space.

Fixes: 7d8905d06405 ("serial: 8250_pci: Enable device after we check black list")
Reported-by: Nikola Ciprich <nikola.ciprich@linuxbox.cz>
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Tested-by: Nikola Ciprich <nikola.ciprich@linuxbox.cz>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

1 files changed, 7 insertions, 3 deletions

diff --git a/drivers/tty/serial/8250/8250_pci.c b/drivers/tty/serial/8250/8250_pci.c
index 54adf8d56350..d580625acc79 100644
--- a/drivers/tty/serial/8250/8250_pci.c
+++ b/drivers/tty/serial/8250/8250_pci.c
@@ -3387,11 +3387,9 @@ static int serial_pci_is_class_communication(struct pci_dev *dev)
         /*
          * If it is not a communications device or the programming
          * interface is greater than 6, give up.
-         *
-         * (Should we try to make guesses for multiport serial devices
-         * later?)
          */
         if ((((dev->class >> 8) != PCI_CLASS_COMMUNICATION_SERIAL) &&
+             ((dev->class >> 8) != PCI_CLASS_COMMUNICATION_MULTISERIAL) &&
              ((dev->class >> 8) != PCI_CLASS_COMMUNICATION_MODEM)) ||
             (dev->class & 0xff) > 6)
                 return -ENODEV;
@@ -3428,6 +3426,12 @@ serial_pci_guess_board(struct pci_dev *dev, struct pciserial_board *board)
 {
         int num_iomem, num_port, first_port = -1, i;
 
+        /*
+         * Should we try to make guesses for multiport serial devices later?
+         */
+        if ((dev->class >> 8) == PCI_CLASS_COMMUNICATION_MULTISERIAL)
+                return -ENODEV;
+
         num_iomem = num_port = 0;
         for (i = 0; i < PCI_NUM_BAR_RESOURCES; i++) {
                 if (pci_resource_flags(dev, i) & IORESOURCE_IO) {