Subject: Re: CVS [email-masked]: linux

From: "Maciej W. Rozycki" <[email-masked]>
Date: Mon, 19 Aug 2002 14:35:19 +0200 (MET DST)

On Mon, 12 Aug 2002, Ralf Baechle wrote:

> Modified files:
> 	arch/mips      : config-shared.in defconfig defconfig-decstation 
> 	                 defconfig-ip22 defconfig-nino defconfig-osprey 
> 	                 defconfig-sb1250-swarm defconfig-sead 
> 	arch/mips64    : defconfig-ip22 defconfig-sb1250-swarm 
> 	                 defconfig-sead 
> 
> Log message:
> 	Make CONFIG_IDE selectable independant of the bus type.

 Hmm, what's the intent of the change?  IDE, or more properly ATA, was
originally an ISA-only device and is still only available as ISA-style
implementations, AFAIK.  I'd prefer it to be available only if any of
CONFIG_ISA, CONFIG_EISA, CONFIG_PCI (unsure about CONFIG_MCA) is set.

 That said, the place for such decisions seems to be inappropriate
currently.  It'd be much more elegant just to source all relevant drivers,
net, etc. Config.in scripts unconditionally and make global enable/disable
decisions at the top of the relevant script, like e.g. 
drivers/message/i2o/Config.in already does. 

-- 
+  Maciej W. Rozycki, Technical University of Gdansk, Poland   +
+--------------------------------------------------------------+
+        e-mail: [email-masked], PGP key available        +

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From: Alan Cox <[email-masked]>
Date: 19 Aug 2002 13:57:03 +0100

> CONFIG_ISA, CONFIG_EISA, CONFIG_PCI (unsure about CONFIG_MCA) is set.

We support ATA devices attached to arbitary busses. The newest ATA code
supports arbitary mmio/pio addressing mechanisms. You don't need ISA or
an ISA like bus.

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From: "Maciej W. Rozycki" <[email-masked]>
Date: Mon, 19 Aug 2002 15:22:22 +0200 (MET DST)

> supports arbitary mmio/pio addressing mechanisms. You don't need ISA or

 Hmm, does such hardware already exist?  I don't think it's reasonable to
make some code available to a user in a configuration that will never make
use of it.  E.g. a plain TURBOchannel box (or one with no I/O bus) won't
ever see a native ATA device (SCSI to ATA bridges obviously don't count). 
I'll check if the code builds at all.

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From: Alan Cox <[email-masked]>
Date: 19 Aug 2002 14:56:23 +0100

> I'll check if the code builds at all. 

Sure. There are embedded devices with onboard IDE controller logic. I
don't know about in mipsdom but certainly elsewhere.

I'm not aware of turdochannel IDE but there is a homebrew QBUS IDE
project

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From: Ralf Baechle <[email-masked]>
Date: Mon, 19 Aug 2002 15:42:15 +0200

> drivers/message/i2o/Config.in already does. 

Even before the changes Alan mentioned we had a bunch of machines like the
SWARM which had PCI but it's PIO IDE adapter wasn't living on the PCI bus.
So disabling PCI on that machine would disable IDE also.  Other machines
had IDE on PCMCIA with the PCMCIA bridge not hanging off an (E)ISA or PCI
bridge.  Basically I could have changed that if statement into an
increasingly obscure and braindamagedly complex if statement.

  Ralf

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From: "Maciej W. Rozycki" <[email-masked]>
Date: Tue, 20 Aug 2002 16:10:48 +0200 (MET DST)

> increasingly obscure and braindamagedly complex if statement.

 Well, that would be of questional benefit, indeed.