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* RE: [parisc-linux] Re: Presicionbook success
@ 2003-04-16 14:00 "Beerse, Corné"
  2003-04-16 14:09 ` M. Grabert
  0 siblings, 1 reply; 16+ messages in thread
From: "Beerse, Corné" @ 2003-04-16 14:00 UTC (permalink / raw)
  To: 'M. Grabert', Matthew Wilcox; +Cc: Gavin Hubbard, parisc-linux

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> -----Original Message-----
> From: M. Grabert [mailto:xam@cs.ucc.ie]
> Sent: woensdag 16 april 2003 15:36
> To: Matthew Wilcox
> Cc: Gavin Hubbard; parisc-linux@lists.parisc-linux.org
> Subject: Re: [parisc-linux] Re: Presicionbook success
> 
> 
> On Wed, 16 Apr 2003, Matthew Wilcox wrote:
> 
> > On Thu, Apr 17, 2003 at 01:15:31AM +1200, Gavin Hubbard wrote:
> > > Before anyone loses too much sleep over this, the 
> Precisionbook has
> > > internal SCSI-IDE bridges that sit between the HBA and 
> the drives. I
> > > believe a similar system was used in some of the earlier 
> Apple Powerbooks.
> >
> > Yep, someone pointed that out in an earlier email.  I'm 
> just trying to
> > figure out how to handle this for the best.
> >
> > 1) Provide a pci quirk that deletes the IDE device from the bus
> > 2) Hack the IDE driver to not claim that device if it's on 
> a PrecisionBook
> > 3) Ignore the scsi device and let the IDE driver drive the chips
> > 4) Er.. something else.
> 
> The initialization of the CMD PCI0643 IDE controller fails when using
> the ESIEE kernel (which has support built-in for this chip).
> Something like "failed to get IRQ, will probe later".
> 
> So no devices were found on the IDE bus, just on the LASI SCSI.
> Probably it's the best just to use SCSI and not to use IDE 
> support at all ...


Is this something like
http://www6.tomshardware.com/storage/20030130/index.html ? Then you
(electronically) cannot find any ide at all, its hidden behind the scsi
interface. If you see part of it, then best to try to handle it as good as
possible (try 'not at all' for a start). I think the 'will probe later' can
be canceled, triggered by a found scsi interface.

For what its worth, I think the IRQ is hooked to the scsi interface, not to
the processor.

btw, what does an `ioscan` from HP-UX report? I guess it only sees scsi.


CBee



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* RE: [parisc-linux] Re: Presicionbook success
@ 2003-04-16 15:05 "Beerse, Corné"
  0 siblings, 0 replies; 16+ messages in thread
From: "Beerse, Corné" @ 2003-04-16 15:05 UTC (permalink / raw)
  To: 'M. Grabert', "Beerse, Corné"
  Cc: Matthew Wilcox, Gavin Hubbard, parisc-linux

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> -----Original Message-----
> From: M. Grabert [mailto:xam@cs.ucc.ie]
> Sent: woensdag 16 april 2003 16:18
> 
> On Wed, 16 Apr 2003, [iso-8859-1] "Beerse, Corné" wrote:
> 
> > This gives me more and more the impression it is definitly 
> some predecessor
> > of http://www6.tomshardware.com/storage/20030130/index.html
> >
>>>>>>>>>>>>>>>>>. snip snip <<<<<<<<<<<<<
> 
> As stated in my earlier mails, it
> 
> - hangs (I waited for quite a while!)
> - or continues (if ide=nodma is used)

Then I think the next happens: The ide interface-chip is somehow detected
and the system pauses while nothing can continue. I think the cpu steps
aside to have some dma passing by. It either waits for some dma to happen or
for a note it can continue. Which never happen and never will happen since
the ide interface-chip does this dma to the scsi controler, not to the
cpu-memory.

In this special case, the cpu should not ask the chip if it does dma, the
chip sure does dma but it does it not against core memory but against the
scsi controler. This will be verry hard to detect from the cpu side. I think
the nicest implementation is to use the ide=nodma, either manually or
carefully if a precisionbook is detected.


CBee

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^ permalink raw reply	[flat|nested] 16+ messages in thread
* RE: [parisc-linux] Re: Presicionbook success
@ 2003-04-16 14:13 "Beerse, Corné"
  2003-04-16 14:18 ` M. Grabert
  0 siblings, 1 reply; 16+ messages in thread
From: "Beerse, Corné" @ 2003-04-16 14:13 UTC (permalink / raw)
  To: 'M. Grabert', Matthew Wilcox; +Cc: Gavin Hubbard, parisc-linux

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> -----Original Message-----
> From: M. Grabert [mailto:xam@cs.ucc.ie]
> 
> On Wed, 16 Apr 2003, Matthew Wilcox wrote:
> 
> > Date: Wed, 16 Apr 2003 14:44:33 +0100
> >
> > On Wed, Apr 16, 2003 at 02:36:25PM +0100, M. Grabert wrote:
> 
> [...]
> 
> > > The initialization of the CMD PCI0643 IDE controller 
> fails when using
> > > the ESIEE kernel (which has support built-in for this chip).
> > > Something like "failed to get IRQ, will probe later".
> >
> > Oh, I thought you said the kernel hung when probing with 
> this driver.
> > If it just whines about being unable to do anything, that's 
> no problem.
> 
> Maybe I was a little bit confusing to you:
> 
> 1. Using a kernel with CMD IDE support, it will hang with the message
>    "will probe IRQs later" ...
> 2. it will not hang if you pass a ide=nodma, but then it will show
>    no devices
> 3. It will just boot fine without any CMD IDE support in the kernel
> 
> > > So no devices were found on the IDE bus, just on the LASI SCSI.
> > > Probably it's the best just to use SCSI and not to use IDE support at
all ...
> >
> > *nod*.  It might be fun for someone to play with fixing the IDE driver,
> > but I don't think that's necessary.

This gives me more and more the impression it is definitly some predecessor
of http://www6.tomshardware.com/storage/20030130/index.html

I think the ide interface is not perfectly hidden behind the scsi interface,
the cpu can still somehow recognize the ide interface. The ide interface
cannot do dma and irq since that is hooked to the scsi interface, not to the
cpu/memory. Hence, I think the best the ide driver can do is not to try
later but to be disabled at all. Btw, what happens if the ide says to try
later, is there a total system pause (resulting in a halt)? or does the
remainder of the system continue (and is it save to ignore)?


CBee

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^ permalink raw reply	[flat|nested] 16+ messages in thread
[parent not found: <20030416123824.22413.48893.Mailman@dsl2.external.hp.com>]

end of thread, other threads:[~2003-04-18  4:41 UTC | newest]

Thread overview: 16+ messages (download: mbox.gz follow: Atom feed
-- links below jump to the message on this page --
2003-04-16 14:00 [parisc-linux] Re: Presicionbook success "Beerse, Corné"
2003-04-16 14:09 ` M. Grabert
2003-04-16 14:15   ` Matthew Wilcox
2003-04-16 14:20     ` Bjorn Helgaas
2003-04-16 14:41   ` Alan Cox
2003-04-17  1:18     ` Stan Sieler
2003-04-18  4:41     ` Grant Grundler
  -- strict thread matches above, loose matches on Subject: below --
2003-04-16 15:05 "Beerse, Corné"
2003-04-16 14:13 "Beerse, Corné"
2003-04-16 14:18 ` M. Grabert
     [not found] <20030416123824.22413.48893.Mailman@dsl2.external.hp.com>
2003-04-16 13:15 ` Gavin Hubbard
2003-04-16 13:27   ` Matthew Wilcox
2003-04-16 13:36     ` M. Grabert
2003-04-16 13:44       ` Matthew Wilcox
2003-04-16 13:48         ` M. Grabert
2003-04-16 15:02   ` Alan Cox

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