4.15-stable review patch. If anyone has any objections, please let me know.
------------------
From: Andy Shevchenko <andriy.shevchenko@xxxxxxxxxxxxxxx>
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@xxxxxxxxxxx>
Signed-off-by: Andy Shevchenko <andriy.shevchenko@xxxxxxxxxxxxxxx>
Tested-by: Nikola Ciprich <nikola.ciprich@xxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
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) {