[PATCH 4.14 201/205] serial: 8250_pci: Make PCI class test non fatal

[Greg Kroah-Hartman]

4.14-stable review patch.  If anyone has any objections, please let me know.

------------------

From: Andy Shevchenko <andriy.shevchenko@xxxxxxxxxxxxxxx>

commit 824d17c57b0abbcb9128fb3f7327fae14761914b upstream.

As has been reported the National Instruments serial cards have broken
PCI class.

The commit 7d8905d06405

  ("serial: 8250_pci: Enable device after we check black list")

made the PCI class check mandatory for the case when device is listed in
a quirk list.

Make PCI class test non fatal to allow broken card be enumerated.

Fixes: 7d8905d06405 ("serial: 8250_pci: Enable device after we check black list")
Cc: stable <stable@xxxxxxxxxxxxxxx>
Reported-by: Guan Yung Tseng <guan.yung.tseng@xxxxxx>
Tested-by: Guan Yung Tseng <guan.yung.tseng@xxxxxx>
Tested-by: KHUENY.Gerhard <Gerhard.KHUENY@xxxxxxxxxxxxx>
Signed-off-by: Andy Shevchenko <andriy.shevchenko@xxxxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>

---
 drivers/tty/serial/8250/8250_pci.c |    9 +++++----
 1 file changed, 5 insertions(+), 4 deletions(-)

--- a/drivers/tty/serial/8250/8250_pci.c
+++ b/drivers/tty/serial/8250/8250_pci.c
@@ -3425,6 +3425,11 @@ static int
 serial_pci_guess_board(struct pci_dev *dev, struct pciserial_board *board)
 {
 	int num_iomem, num_port, first_port = -1, i;
+	int rc;
+
+	rc = serial_pci_is_class_communication(dev);
+	if (rc)
+		return rc;
 
 	/*
 	 * Should we try to make guesses for multiport serial devices later?
@@ -3652,10 +3657,6 @@ pciserial_init_one(struct pci_dev *dev,
 
 	board = &pci_boards[ent->driver_data];
 
-	rc = serial_pci_is_class_communication(dev);
-	if (rc)
-		return rc;
-
 	rc = serial_pci_is_blacklisted(dev);
 	if (rc)
 		return rc;