[PATCH] Char: correct pci_get_device changes

Commits 881a8c120acf7ec09c90289e2996b7c70f51e996 and
efe1ec27837d6639eae82e1f5876910ba6433c3f corrects pci device matching in
only one way; it no longer oopses/crashes, despite hotplug is not solved
in these changes.

Whenever pci_find_device -> pci_get_device change is performed, also
pci_dev_get and pci_dev_put should be in most cases called to properly
handle hotplug.  This patch does exactly this thing -- increase refcount
to let kernel know, that we are using this piece of HW just now.

It affects moxa and rio char drivers.

Cc: <R.E.Wolff@BitWizard.nl>
Acked-by: Amit Gud <gud@eth.net>
Acked-by: Greg Kroah-Hartman <gregkh@suse.de>
Acked-by: Alan Cox <alan@lxorguk.ukuu.org.uk>
Signed-off-by: Jiri Slaby <jirislaby@gmail.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

1 files changed, 9 insertions, 0 deletions

diff --git a/drivers/char/moxa.c b/drivers/char/moxa.c
index b401383808c2..96cb1f07332b 100644
--- a/drivers/char/moxa.c
+++ b/drivers/char/moxa.c
@@ -130,6 +130,7 @@ static moxa_isa_board_conf moxa_isa_boards[] =
 typedef struct _moxa_pci_devinfo {
         ushort busNum;
         ushort devNum;
+        struct pci_dev *pdev;
 } moxa_pci_devinfo;
 
 typedef struct _moxa_board_conf {
@@ -324,6 +325,9 @@ static int moxa_get_PCI_conf(struct pci_dev *p, int board_type, moxa_board_conf
         board->busType = MOXA_BUS_TYPE_PCI;
         board->pciInfo.busNum = p->bus->number;
         board->pciInfo.devNum = p->devfn >> 3;
+        board->pciInfo.pdev = p;
+        /* don't lose the reference in the next pci_get_device iteration */
+        pci_dev_get(p);
 
         return (0);
 }
@@ -493,6 +497,11 @@ static void __exit moxa_exit(void)
         if (tty_unregister_driver(moxaDriver))
                 printk("Couldn't unregister MOXA Intellio family serial driver\n");
         put_tty_driver(moxaDriver);
+
+        for (i = 0; i < MAX_BOARDS; i++)
+                if (moxa_boards[i].busType == MOXA_BUS_TYPE_PCI)
+                        pci_dev_put(moxa_boards[i].pciInfo.pdev);
+
         if (verbose)
                 printk("Done\n");
 }