[PATCH] Char: correct pci_get_device changes

Commits 881a8c12 and
efe1ec27 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>

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");
 }

drivers/char/rio/host.h

@@ -44,6 +44,7 @@
 **    the host.
 */
 struct Host {
+	struct pci_dev *pdev;
 	unsigned char Type;		/* RIO_EISA, RIO_MCA, ... */
 	unsigned char Ivec;		/* POLLED or ivec number */
 	unsigned char Mode;		/* Control stuff */

drivers/char/rio/rio_linux.c

@@ -1017,6 +1017,10 @@ static int __init rio_init(void)
 			rio_dprintk(RIO_DEBUG_PROBE, "Hmm Tested ok, uniqid = %x.\n", p->RIOHosts[p->RIONumHosts].UniqueNum);
 
 			fix_rio_pci(pdev);
+
+			p->RIOHosts[p->RIONumHosts].pdev = pdev;
+			pci_dev_get(pdev);
+
 			p->RIOLastPCISearch = 0;
 			p->RIONumHosts++;
 			found++;
@@ -1066,6 +1070,9 @@ static int __init rio_init(void)
 			    ((readb(&p->RIOHosts[p->RIONumHosts].Unique[1]) & 0xFF) << 8) | ((readb(&p->RIOHosts[p->RIONumHosts].Unique[2]) & 0xFF) << 16) | ((readb(&p->RIOHosts[p->RIONumHosts].Unique[3]) & 0xFF) << 24);
 			rio_dprintk(RIO_DEBUG_PROBE, "Hmm Tested ok, uniqid = %x.\n", p->RIOHosts[p->RIONumHosts].UniqueNum);
 
+			p->RIOHosts[p->RIONumHosts].pdev = pdev;
+			pci_dev_get(pdev);
+
 			p->RIOLastPCISearch = 0;
 			p->RIONumHosts++;
 			found++;
@@ -1181,6 +1188,8 @@ static void __exit rio_exit(void)
 		}
 		/* It is safe/allowed to del_timer a non-active timer */
 		del_timer(&hp->timer);
+		if (hp->Type == RIO_PCI)
+			pci_dev_put(hp->pdev);
 	}
 
 	if (misc_deregister(&rio_fw_device) < 0) {