Jean, On Jan 24, 2005, at 8:12 AM, Jean Delvare wrote: > > Hi Oliver, > >> i am running gentoo linux 2.6.10-r6 on a via EPiA-m board that uses a >> VT835 southbridge. when you i use the i2c bus, the clock and data >> lines appear to be running at 16KHz not the more normal 100kHz or >> 400KHz speeds > > 100kHz and 400kHz are *maximum* frequency for standard and high-speed > *I2C* busses. What your VIA bridge really is is an SMBus, so it must > run > at a speed between 10kHz and 100kHz if I remember correctly. > > As a matter of fact, I already measured both my VIA and Intel SMBus > chips > at 16kHz, exactly like you. So I am not surprised at all by what you > are > reporting. > > BTW, may I ask how you did measure the frequency? I hooked an oscilloscope to the clock and data pins. > >> Do you have any documentation on what the registers inside the via >> southbridge chips do, so i can try and fix this problem? If not do, >> you know if this is a known problem with the via chip sets? > > As far as I know, there is no way to change the clock for the Intel > SMBus. I have no documentation for the VIA chips but I would suspect > that you cannot change it there either. > > May I know the SMBus speed (or rather slowness) is so important to you? The 3rd party board I am trying to use does not seem to like the slower clock rate. > > Thanks, > -- > Jean Delvare >
