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authorJens Rottmann <JRottmann@LiPPERTEmbedded.de>2009-06-22 19:51:49 +0400
committerLinus Torvalds <torvalds@linux-foundation.org>2009-06-22 22:28:59 +0400
commite2434dc1c19412639dd047a4d4eff8ed0e5d0d50 (patch)
treeaa723d51dedc8c404205877c9885af09906e6d18 /drivers/parport
parent752a4787511bf7515f99609ff4ae52341b5bfcde (diff)
downloadlinux-e2434dc1c19412639dd047a4d4eff8ed0e5d0d50.tar.xz
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: Jens Rottmann <JRottmann@LiPPERTEmbedded.de> Signed-off-by: Alan Cox <alan@linux.intel.com> Cc: <stable@kernel.org> Acked-by: Jeff Garzik <jgarzik@redhat.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'drivers/parport')
-rw-r--r--drivers/parport/parport_pc.c31
1 files changed, 25 insertions, 6 deletions
diff --git a/drivers/parport/parport_pc.c b/drivers/parport/parport_pc.c
index 151bf5bc8afe..7f1cca701c11 100644
--- a/drivers/parport/parport_pc.c
+++ b/drivers/parport/parport_pc.c
@@ -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 */