Re: radeonfb i2c regression post-2.6.18.

Benjamin Herrenschmidt
2007-11-24T22:26:18Z

> Very strange indeed. Another possibility is that there is a hardware
> monitoring chip connected to one of the Radeon adapter's I2C buses, and
> that holding the I2C lines prevents reading from it, so whatever is
> responsible for controlling the temperature prefers to play it safe and
> shuts everything down. Somehow it seems more realistic than an actual
> overheating (3 seconds is a very short period of time for that), but
> we'd need the exact schematics of the hardware, and the details of the
> thermal control system, to validate this theory.
>
> Anyway, no need to worry anymore now that the bug is fixed :)

Actually, that's a possibility yes, though generally Apple put all temp.
monitoring chips elsewhere, it could well be the case.

Ben.