nope nope wrote:
>
> Normally I'd go straight to the writer of the driver with this problem but
> he's anonymous, soo...
> I've been getting the same hard freezes as a lot of people who are trying to
> use Neomagic nm256 audio. What's causing the lockups, at least on my Dell
> Latitude LS, is the ac97_codec driver trying to read (not write) a few
> standard AC97 registers. In particular anytime the AC97_RESET register
> (defined in ac97.h as 0x00) is accessed the machine instantly crashes. This
> also occurs for several other registers. Does anyone have any idea why this
> might be occuring? It's not like the driver is trying to _write_ to any
> memory - at least then the crashes would make a little bit of sense. Just
> reading those registers kills it. The Windows drivers for this chip work
> fine; I wish I knew a bit more about how to delve into the interals of
> Windows so I could see just how that driver finesses the AC97 registers
> without locking the machine. Is anyone aware of any sort of conflict that
> I'm missing here? Advice on how to proceed? Thanks!
I'm new to this list and don't know too much about driver programming,
but I had similar problems writing some assembly programs years ago.
My problems were mainly caused by doing 16-bit access to 8-bit registers.
The CPU-/Chipset does some automatic serialisation of those requests, but
sometimes the timing is critical. For my problems it helped to split the
requests into 8-bit io's with some NOP's in between ...
HTH
Karl
"... sometimes you get answers
to questions you never asked ..."
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This archive was generated by hypermail 2b29 : Mon Jul 31 2000 - 21:00:22 EST