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Diffstat (limited to 'Documentation/i2c/busses/i2c-piix4')
| -rw-r--r-- | Documentation/i2c/busses/i2c-piix4 | 14 |
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. Please note that you don't need to do that in all cases, just when the SMBus is not working properly. + + +Hardware-specific issues +------------------------ + +This driver will refuse to load on IBM systems with an Intel PIIX4 SMBus. +Some of these machines have an RFID EEPROM (24RF08) connected to the SMBus, +which can easily get corrupted due to a state machine bug. These are mostly +Thinkpad laptops, but desktop systems may also be affected. We have no list +of all affected systems, so the only safe solution was to prevent access to +the SMBus on all IBM systems (detected using DMI data.) + +For additional information, read: +http://www2.lm-sensors.nu/~lm78/cvs/lm_sensors2/README.thinkpad |