Messages in this thread |  | | Date | Thu, 29 Nov 2001 18:11:21 -0700 | From | Richard Gooch <> | Subject | Re: IDE controller detection 2.4 +devfs |
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Rene Rebe writes: > On Thu, 29 Nov 2001 17:34:11 -0700 > Richard Gooch <rgooch@ras.ucalgary.ca> wrote: > > Um, from your previous message, it seems that host numbering doesn't > > change depending on BIOS settings. > > It was the first storry - my older Athlon.
OK, so, just to be clear, BIOS settings are *not* changing host numbering. IOW, "host1" always refers to the same piece of hardware, whether or not "host1" appears in devfs.
> > So what exactly is happening? And what is the problem? I realise you > > may find the naming a little confusing, but is there an actual > > problem? > > ok - again. > > I have a K6 on an ALI Aladin-5 board and an additional IDE controller > (Promisse). The onboard can be found as /dev/host0 and the additional > Promisse one appears as /dev/host2: > > server1:~ # l /dev/ide/ > total 0 > drwxr-xr-x 1 root root 0 Jan 1 1970 . > drwxr-xr-x 1 root root 0 Jan 1 1970 .. > drwxr-xr-x 1 root root 0 Jan 1 1970 host0 > drwxr-xr-x 1 root root 0 Jan 1 1970 host2 > > The boot messages: [...] > I works - but sucks, because I'm not able to predict the > ide-controller entries in /dev/ide/* because they seem (for me) > randomly on each workstaion I am ...
But it is actually predictable, isn't it? Think of it this way: the IDE subsystem reserves "slots" (host numbers) for installed hardware. If a piece of hardware is disabled in the BIOS, it doesn't mean that the slot won't be reserved.
> (All info from my very first mail ...) > > The other bug is: On a Athlon-600 workstation based on an Irongate > board (Asus-K7M) I have to disable the first (primarry) channel of > the onbaord IDE controller, because it has problem with the UDMA-66 > mode. But when I disable this channel, Linux generates a /dev/ide/host1 > entry - No host0 entry is there. Sure it works - but sucks, too! > (Generates a very unstable feeling in me ...)
The "host0" entry isn't shown, because it is disabled. But to say "when I disable this channel, Linux generates a /dev/ide/host1" isn't correct, and implies a problem where there isn't. The correct way to describe this is: "host0" is my primary onboard IDE controller. It might not appear if I disable it. "host1" is my secondary onboard IDE controller. It has the same name whether or not I disable the primary.
And this is a Feature[tm]. It means that tomorrow when a shiny new drive arrives, you can plug it into your primary channel and enable the channel in the BIOS. You can then boot without having to fix your /etc/fstab, because /dev/ide/host1 is still pointing to the same devices.
The only thing that confuses me is why the secondary onboard channel is /dev/ide/host1 rather than /dev/ide/host0/bus1.
Regards,
Richard.... Permanent: rgooch@atnf.csiro.au Current: rgooch@ras.ucalgary.ca - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
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