ADM1032 Config Reg Check Incorrect

[ticket]

In lm90_detect routine, adm1032 entry (sensors-detect:3478), the config register check ANDs the resulting byte with 0x3f. According to the datasheet, only the two MS bits are modifiable, with the 6 LS bits reserved. The result of the config. register read should be ANDED with 0xC0 to determine that the ADM1032 is present and operational. This caused sensors-detect to fail to detect the ADM0132 on my system (Versalogic EBX-12), with config register returning 0x13. The others fields were correct.

Datasheet:  http://www.analog.com/UploadedFiles/Data_Sheets/ADM1032.pdf

[khali]

The code is correct. We can't check the used bits of the configuration register, as their value can change. We want to check the unused bits, because their value should always be 0. It happens to not be the case on your Versalogic EBX-12, for a reason I ignore.

Either your chip has a power-up value for this register which differs from the documented value. What exact version of the ADM1032 chip is it? Or maybe it is some clone? Or something is writing to this register between power-up and the moment you run sensors-detect. I have no idea why someone would want to do that though, you'll have to investigate.

BTW, this problem was already reported by the Versalogic support team:
 http://lists.lm-sensors.org/pipermail/lm-sensors/2005-December/014568.html
And my reply back then was the very same.

[khali]

No feedback for a long time, closing.