[patch 086/108] parport_pc: after superio probing restore original register values

Greg KH
2009-07-01T01:12:13Z

[-- Attachment #1: parport_pc-after-superio-probing-restore-original-register-values.patch --]
[-- Type: text/plain, Size: 4318 bytes --]

2.6.30-stable review patch. If anyone has any objections, please let us know.

------------------

From: Jens Rottmann <JRottmann@LiPPERTEmbedded.de>

commit e2434dc1c19412639dd047a4d4eff8ed0e5d0d50 upstream.

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: Jens Rottmann <JRottmann@LiPPERTEmbedded.de>
Signed-off-by: Alan Cox <alan@linux.intel.com>
Acked-by: Jeff Garzik <jgarzik@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

---
drivers/parport/parport_pc.c | 31 +++++++++++++++++++++++++------
1 file changed, 25 insertions(+), 6 deletions(-)

--- a/drivers/parport/parport_pc.c
+++ b/drivers/parport/parport_pc.c
@@ -1413,11 +1413,13 @@ static void __devinit decode_smsc(int ef

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);
@@ -1437,6 +1439,8 @@ static void __devinit winbond_check(int
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 */

@@ -1447,11 +1451,15 @@ 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);
@@ -1470,6 +1478,10 @@ static void __devinit winbond_check2(int
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 */

@@ -1480,11 +1492,13 @@ 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);
@@ -1508,6 +1522,8 @@ static void __devinit smsc_check(int io,
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 */
@@ -1544,11 +1560,12 @@ static void __devinit detect_and_report_
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);
@@ -1568,8 +1585,10 @@ static void __devinit detect_and_report_
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 */