Patch "serial: 8250_pci: Don't fail on multiport card class" has been added to the 4.15-stable tree

[<gregkh@linuxfoundation.org>]

This is a note to let you know that I've just added the patch titled

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

to the 4.15-stable tree which can be found at:
    http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary

The filename of the patch is:
     serial-8250_pci-don-t-fail-on-multiport-card-class.patch
and it can be found in the queue-4.15 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@vger.kernel.org> know about it.


>From e7f3e99cb1a667d04d60d02957fbed58b50d4e5a Mon Sep 17 00:00:00 2001
From: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Date: Fri, 2 Feb 2018 20:39:13 +0200
Subject: serial: 8250_pci: Don't fail on multiport card class

From: Andy Shevchenko <andriy.shevchenko@linux.intel.com>

commit e7f3e99cb1a667d04d60d02957fbed58b50d4e5a upstream.

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>

---
 drivers/tty/serial/8250/8250_pci.c |   10 +++++++---
 1 file changed, 7 insertions(+), 3 deletions(-)

--- 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_communica
 	/*
 	 * 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 *d
 {
 	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) {


Patches currently in stable-queue which might be from andriy.shevchenko@linux.intel.com are

queue-4.15/serial-8250_pci-don-t-fail-on-multiport-card-class.patch