Commit e2434dc1 authored by Jens Rottmann's avatar Jens Rottmann Committed by Linus Torvalds
Browse files

parport_pc: after superio probing restore original register values 



CONFIG_PARPORT_PC_SUPERIO probes for various superio chips by writing
byte sequences to a set of different potential I/O ranges.  But the
probed ranges are not exclusive to parallel ports.  Some of our boards
just happen to have a watchdog in one of them.  Took us almost a week
to figure out why some distros reboot without warning after running
flawlessly for 3 hours.  For exactly 170 = 0xAA minutes, that is ...

Fixed by restoring original values after probing.  Also fixed too small
request_region() in detect_and_report_it87().

Signed-off-by: default avatarJens Rottmann <JRottmann@LiPPERTEmbedded.de>
Signed-off-by: default avatarAlan Cox <alan@linux.intel.com>
Cc: <stable@kernel.org>
Acked-by: default avatarJeff Garzik <jgarzik@redhat.com>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent 752a4787

drivers/parport/parport_pc.c

+25 −6
Original line number Diff line number Diff line
@@ -1471,11 +1471,13 @@ static void __devinit decode_smsc(int efer, int key, int devid, int devrev) 


static void __devinit winbond_check(int io, int key)

{

	int devid, devrev, oldid, x_devid, x_devrev, x_oldid;

	int origval, devid, devrev, oldid, x_devid, x_devrev, x_oldid;



	if (!request_region(io, 3, __func__))

		return;



	origval = inb(io); /* Save original value */



	/* First probe without key */

	outb(0x20, io);

	x_devid = inb(io + 1);
@@ -1495,6 +1497,8 @@ static void __devinit winbond_check(int io, int key) 
	oldid = inb(io + 1);

	outb(0xaa, io);    /* Magic Seal */



	outb(origval, io); /* in case we poked some entirely different hardware */



	if ((x_devid == devid) && (x_devrev == devrev) && (x_oldid == oldid))

		goto out; /* protection against false positives */
@@ -1505,11 +1509,15 @@ out: 


static void __devinit winbond_check2(int io, int key)

{

	int devid, devrev, oldid, x_devid, x_devrev, x_oldid;

	int origval[3], devid, devrev, oldid, x_devid, x_devrev, x_oldid;



	if (!request_region(io, 3, __func__))

		return;



	origval[0] = inb(io); /* Save original values */

	origval[1] = inb(io + 1);

	origval[2] = inb(io + 2);



	/* First probe without the key */

	outb(0x20, io + 2);

	x_devid = inb(io + 2);
@@ -1528,6 +1536,10 @@ static void __devinit winbond_check2(int io, int key) 
	oldid = inb(io + 2);

	outb(0xaa, io);    /* Magic Seal */



	outb(origval[0], io); /* in case we poked some entirely different hardware */

	outb(origval[1], io + 1);

	outb(origval[2], io + 2);



	if (x_devid == devid && x_devrev == devrev && x_oldid == oldid)

		goto out; /* protection against false positives */
@@ -1538,11 +1550,13 @@ out: 


static void __devinit smsc_check(int io, int key)

{

	int id, rev, oldid, oldrev, x_id, x_rev, x_oldid, x_oldrev;

	int origval, id, rev, oldid, oldrev, x_id, x_rev, x_oldid, x_oldrev;



	if (!request_region(io, 3, __func__))

		return;



	origval = inb(io); /* Save original value */



	/* First probe without the key */

	outb(0x0d, io);

	x_oldid = inb(io + 1);
@@ -1566,6 +1580,8 @@ static void __devinit smsc_check(int io, int key) 
	rev = inb(io + 1);

	outb(0xaa, io);    /* Magic Seal */



	outb(origval, io); /* in case we poked some entirely different hardware */



	if (x_id == id && x_oldrev == oldrev &&

	    x_oldid == oldid && x_rev == rev)

		goto out; /* protection against false positives */
@@ -1602,11 +1618,12 @@ static void __devinit detect_and_report_smsc(void) 
static void __devinit detect_and_report_it87(void)

{

	u16 dev;

	u8 r;

	u8 origval, r;

	if (verbose_probing)

		printk(KERN_DEBUG "IT8705 Super-IO detection, now testing port 2E ...\n");

	if (!request_region(0x2e, 1, __func__))

	if (!request_region(0x2e, 2, __func__))

		return;

	origval = inb(0x2e);		/* Save original value */

	outb(0x87, 0x2e);

	outb(0x01, 0x2e);

	outb(0x55, 0x2e);
@@ -1626,8 +1643,10 @@ static void __devinit detect_and_report_it87(void) 
		outb(r | 8, 0x2F);

		outb(0x02, 0x2E);	/* Lock */

		outb(0x02, 0x2F);

	} else {

		outb(origval, 0x2e);	/* Oops, sorry to disturb */

	}

	release_region(0x2e, 1);

	release_region(0x2e, 2);

}

#endif /* CONFIG_PARPORT_PC_SUPERIO */

CRA Git | Maintained and supported by SUSTech CRA and CCSE