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List:       linux-kernel
Subject:    Re: [PATCH] x86: provide a DMI based port 0x80 I/O delay override
From:       "H. Peter Anvin" <hpa () zytor ! com>
Date:       2007-12-31 23:41:45
Message-ID: 47797E39.7090208 () zytor ! com
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Alan Cox wrote:
>> However, assuming a bus clock of 6 MHz should be safe (167 ns).
> 
> Agreed - or ISA timings directly. Boxes using WD80x3 are not going to
> have a TSC so might as well stick with port 0x80 as they have done just
> fine for the past 15 years.
> 
>> None of this really helps with *memory-mapped* 8390, though, since 
>> memory mapped writes can be posted.  Putting any IOIO transaction in the 
> 
> ISA isn't posted only PCI.
> 
> PCI 8390 clones seem to be a mix of ASICs and 8390x chips with
> some quite disgusting FPGA glue logic.
> 

ISA isn't posted no, but on several chipsets the upstream PCI bus will 
post MMIO writes to ISA space regardless of the spec.

	-hpa
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