Re: [0/4][via-rhine] Improvements

Roger Luethi (rl@hellgate.ch)
Sat, 15 Feb 2003 23:52:04 +0100


On Sat, 15 Feb 2003 16:49:24 -0500, Jeff Garzik wrote:
> I applied the patch, but I meant more that wait_for_reset seems
> questionable. There is generally a PIO or MMIO write preceding
> wait_for_reset function call, and then the function delays. If the PCI
> write is posted, for example, which at least my own Via EPIA does, then
> you cannot be guaranteed the timing of
> write[bwl]()
> udelay(5)
>
> PCI writes must be flushed, by doing a read[bwl]().

Thanks for raising that issue. It is my understanding that PIO ops are
synchronous (on IA-32). If that is correct, problems should only occur if
the driver is built with MMIO support, no?

I have been building the driver without MMIO for quite a while to eliminate
one source of problems for now.

> what the exact handling is... and randomly placed udelay() calls are,
> unfortunately, sometimes a sign of driver bugs instead of necessary
> hardware delays.

You won't see me rule out driver bugs as a likely explanation for anything
anytime soon ;-).

> I would prefer both user and developer docs go in
> Documentation/networking/via-rhine.txt. It is easy enough to note
> separate sections of the document...

ACK.

Roger
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