On Tue, 1 Jun 1999, Frederick Bruckman wrote:

> On Tue, 1 Jun 1999, Colin Wood wrote:
> 
> The problem with delay() is interesting, but it's not the whole
> answer. I tried forcing a value for delay, and results were still
> inconsistent. The fun one is when you get a kernel that boots half of
> the time, basically at random. I also built a little countdown test
> into my kernel, to test both long and short delays. It's always pretty
> close, no matter what number it comes up with for the delay factor.
> 
> There doesn't seem to be anything critical about that 3ms timing loop.
> It's just waiting for the bus to complete it's reset. Values of 2ms
> and 4ms seemed to work for me (840AV): Guy Santiagla reported that
> only 4ms worked on the Quadra 610. The same set of kernels that worked
> with 2ms and 4ms failed at 3ms. Think about that.
> 
> Now take a hard look at adb_cuda_tickle(). It's a watchdog timer for
> the Cuda hardware. If the Cuda really needs a watchdog, maybe there's
> a bug in the hardware. If so, adb_reinit() needs a watchdog, too.

I really don't understand why changing the timer value will make it work,
but if the delay factor is wrong, all the timing for the ADB stuff will be
off, and who knows what will mess up.

Let's see how Jason's revised delay_factor calculator works.

Take care,

Bill