Hi Juerg, On Mon, 22 Jan 2007 21:14:57 -0800, Juerg Haefliger wrote: > Hi all, > > When running sensors (2.10.1) I get the following adapter information: > emc6d102-i2c-1-2e > Adapter: SMBus nForce2 adapter at 4c40 > > And i2cdump prints the following: > Installed I2C busses: > i2c-5 i2c NVIDIA i2c adapter 2 at 0:05.0 > i2c-4 i2c NVIDIA i2c adapter 1 at 0:05.0 > i2c-3 i2c NVIDIA i2c adapter 0 at 0:05.0 > i2c-2 i2c ivtv i2c driver #0 > i2c-1 smbus SMBus nForce2 adapter at 4c40 > i2c-0 smbus SMBus nForce2 adapter at 4c00 > > But in order to dump the register content of the emc6d102 I have to scan bus > 0: > > jabba:/home/juergh# i2cdump 0 0x2e > No size specified (using byte-data access) > WARNING! This program can confuse your I2C bus, cause data loss and worse! > I will probe file /dev/i2c-0, address 0x2e, mode byte > Continue? [Y/n] y > 0 1 2 3 4 5 6 7 8 9 a b c d e f 0123456789abcdef > 00: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................ > 10: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................ > 20: 00 79 c1 c2 be 80 29 31 46 0b ff ff ff ff ff ff .y????)1F?...... > 30: 55 ff ff 00 00 00 00 00 00 00 00 00 00 00 5c 8a U.............\? > 40: 05 91 40 00 00 ff 00 ff 00 ff 00 ff 00 ff 81 7f ??@...........?? > 50: 81 7f 81 7f ff ff ff ff ff ff ff ff 42 62 62 cb ????........Bbb? > 60: cb db e0 00 55 80 80 5a 5a 3c 64 64 4d 40 40 00 ???.U??ZZ<ddM@@. > 70: 55 ff ff 09 09 09 09 09 09 00 10 00 40 00 ec 18 U..??????.?. at .?? > 80: 7e a4 0e 00 60 90 99 90 c1 00 4d 4d 0b 0b 0d 00 ~??.`????.MM???. > 90: 04 04 04 04 0c 0c 0c 5a f1 c2 00 00 ff 00 ff 00 ???????Z??...... > a0: 00 00 0c 00 02 00 00 0b 0b fe ff fe ff ff ff ff ..?.?..???.?.... > b0: ff 00 00 00 00 00 28 28 0e 0e 2b 2b 00 00 00 00 ......((??++.... > c0: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................ > d0: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................ > e0: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................ > f0: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................ > > Scanning bus 1 on the other hand returns all FFs: > > jabba:/home/juergh# i2cdump 1 0x2c > No size specified (using byte-data access) > WARNING! This program can confuse your I2C bus, cause data loss and worse! > I will probe file /dev/i2c-1, address 0x2c, mode byte > Continue? [Y/n] y > 0 1 2 3 4 5 6 7 8 9 a b c d e f 0123456789abcdef > 00: XX XX XX XX XX XX XX XX XX XX XX XX XX XX XX XX XXXXXXXXXXXXXXXX > 10: XX XX XX XX XX XX XX XX XX XX XX XX XX XX XX XX XXXXXXXXXXXXXXXX > 20: XX XX XX XX XX XX XX XX XX XX XX XX XX XX XX XX XXXXXXXXXXXXXXXX > 30: XX XX XX XX XX XX XX XX XX XX XX XX XX XX XX XX XXXXXXXXXXXXXXXX > 40: XX XX XX XX XX XX XX XX XX XX XX XX XX XX XX XX XXXXXXXXXXXXXXXX > 50: XX XX XX XX XX XX XX XX XX XX XX XX XX XX XX XX XXXXXXXXXXXXXXXX > 60: XX XX XX XX XX XX XX XX XX XX XX XX XX XX XX XX XXXXXXXXXXXXXXXX > 70: XX XX XX XX XX XX XX XX XX XX XX XX XX XX XX XX XXXXXXXXXXXXXXXX > 80: XX XX XX XX XX XX XX XX XX XX XX XX XX XX XX XX XXXXXXXXXXXXXXXX > 90: XX XX XX XX XX XX XX XX XX XX XX XX XX XX XX XX XXXXXXXXXXXXXXXX > a0: XX XX XX XX XX XX XX XX XX XX XX XX XX XX XX XX XXXXXXXXXXXXXXXX > b0: XX XX XX XX XX XX XX XX XX XX XX XX XX XX XX XX XXXXXXXXXXXXXXXX > c0: XX XX XX XX XX XX XX XX XX XX XX XX XX XX XX XX XXXXXXXXXXXXXXXX > d0: XX XX XX XX XX XX XX XX XX XX XX XX XX XX XX XX XXXXXXXXXXXXXXXX > e0: XX XX XX XX XX XX XX XX XX XX XX XX XX XX XX XX XXXXXXXXXXXXXXXX > f0: XX XX XX XX XX XX XX XX XX XX XX XX XX XX XX XX XXXXXXXXXXXXXXXX Which kernel is this? 2.5 and early 2.6 kernels are known for this behavior. It was fixed in 2.6.4. I guess you're using something more recent though. Is this bug reproducible, or did it only happen to you once? When it happens, please run "ls -l /dev/i2c*" (or /dev/i2c/* if your system uses this naming scheme.) I suspect that you have /dev/i2c-1 using minor 0 and /dev/i2c-0 using minor 1. -- Jean Delvare
