Messages in this thread | | | Date | Tue, 05 Aug 2008 02:52:47 +0400 | From | Sergei Shtylyov <> | Subject | Re: Kernel Summit request for Discussion of future of ATA (libata) and IDE |
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Hello, I wrote: >>>>> supported. I couldn't track down where that bit was actually >>>>> defined in the first place, all the way back to ATA-1 it seems to >>>>> be indicated as reserved. Actually, I'm not sure why the drive >>>>> cares in the first place, it would seem like a pure host >>>>> controller issue.. >>>>> >>>> It goes back before IDE into the depths of the original compaq >>>> spec. When >>>> you have a device wired basically directly to the ISA bus (original >>>> IDE) >>>> >>> ISA has only 8/16-bit data bus, so it could not have mattered >>> there... >> >> Depends what a 32bit I/O looks like on the 16bit bus - timing wise. >> > > Two 16-bit reads at addresses 0x1x0 and 0x1x2 with the programmed > recovery time, IIRC... It's just occured to me that in case of the > 16-bit bus it should be how the drive treated the accesses at address > 0x1x2 with IOCS16 asserted that could have mattered. If it honored > them, 32-bit I/O could have worked even on a dumb ISA "controller", if > not -- no way (unless you really had *something* between the ISA and > the IDE cable).
Oh, -IOCS16 is driven by device, not host. I give up then. :-)
MBR, Sergei
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