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authorJean Delvare <khali@linux-fr.org>2006-04-25 07:37:25 -0400
committerGreg Kroah-Hartman <gregkh@suse.de>2006-06-22 14:10:32 -0400
commitf9ba6c04ef1dcf16f7179b7883e9751baaac218e (patch)
tree0d66c8aab1ea1c0343744925e53f7e9111daaff0 /Documentation
parent7aadb8f943f6f8fb48962099cfba05ad0518b0ac (diff)
[PATCH] I2C: i2c-piix4: Document the IBM problem more clearly
Properly document on which systems the i2c-piix4 SMBus driver will refuse to load. Hopefully this will make it clearer for users, which were often wondering why their destop or server systems were detected as laptops. Closes bug #6429. Signed-off-by: Jean Delvare <khali@linux-fr.org> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Diffstat (limited to 'Documentation')
-rw-r--r--Documentation/i2c/busses/i2c-piix414
1 files changed, 14 insertions, 0 deletions
diff --git a/Documentation/i2c/busses/i2c-piix4 b/Documentation/i2c/busses/i2c-piix4
index a706ae6a1b41..921476333235 100644
--- a/Documentation/i2c/busses/i2c-piix4
+++ b/Documentation/i2c/busses/i2c-piix4
@@ -82,3 +82,17 @@ the SMI mode.
82 82
83Please note that you don't need to do that in all cases, just when the SMBus is 83Please note that you don't need to do that in all cases, just when the SMBus is
84not working properly. 84not working properly.
85
86
87Hardware-specific issues
88------------------------
89
90This driver will refuse to load on IBM systems with an Intel PIIX4 SMBus.
91Some of these machines have an RFID EEPROM (24RF08) connected to the SMBus,
92which can easily get corrupted due to a state machine bug. These are mostly
93Thinkpad laptops, but desktop systems may also be affected. We have no list
94of all affected systems, so the only safe solution was to prevent access to
95the SMBus on all IBM systems (detected using DMI data.)
96
97For additional information, read:
98http://www2.lm-sensors.nu/~lm78/cvs/lm_sensors2/README.thinkpad