[FYI] linux 2.6 still not working with PReP (ppc32)

[Sebastian Heutling]

On Sun, 2005-01-02 at 10:39 +0100, Sven Luther wrote:
> On Sun, Jan 02, 2005 at 12:56:29AM +0100, Sebastian Heutling wrote:
> > On Fri, 2004-12-31 at 23:28 +0100, Sven Luther wrote:
> > > On Fri, Dec 31, 2004 at 04:00:49PM +0100, Sebastian Heutling wrote:
> > > > On Fri, 2004-12-31 at 10:55 +0100, Sven Luther wrote:
> > > > > On Mon, Dec 27, 2004 at 03:47:05AM +0100, Christian wrote:
> > > > > > Marc Dietrich schrieb:
> > > > > > >Hi all,
> > > > > > >
> > > > > > >I read this thread about booting a PowerStack with newer kernels. 
> > > > > > >Motivated by this, I tried to compile a 2.6.10 kernel on my machine (with 
> > > > > > >sym53c825a onboard). Sadly, the scsi controller always timeouts during 
> > > > > > >initialisation. I 
> > > > > 
> > > > > I also have some strange issues with network support using the standard debian
> > > > > 2.6.8 kernel. ifconfig upping the decchip ethernet on the powerstack freezes
> > > > > the kernel, and i hear reports of problems on IBM PReP hardware too with not
> > > > > working ethernet, altough there is no freeze.
> > > > > 
> > > > > Any idea on this ? 
> > > > 
> > > > Does it contain the IRQ patch? Where does it boot from SCSI or net? What
> > > > PCI-Devices are installed?
> > > 
> > > Probably not, just the standard debian kernel, i donÃ't remember any irq
> > > patches, but there where a bunch of patches from leighbb. it is done
> > 
> > The patch is the one that is included in 2.6.10 which is mentioned above
> > and this thread already has somewhere in the beginning. I attached it
> > below.
> > I haven't had the time yet to test the 2.6.10 kernel. Maybe there is
> > another problem now ...
> 
> The one with three lines of modified irq lines from tom rini ? I found it in
> google, but i also saw another bunch of prep changes which got in 2.6.9 i

Hmmm ... I didn't realise any other prep changes in 2.6.9


> think. Since debian is still using 2.6.8 and a bunch of backports, these may
> be relevant, i think.

You mean debian/testing?


> 
> Also, i think for some reason i was unsubscribed while the list moved to
> ozlab, and lost maybe the start of the thread, thanks for the attachement.

That explains a lot ;-)


> 
> > > netbooting, and the only pci device installed is the cirruss logic graphic
> > > card.
> > 
> > If you use the standard debian kernel - ok, it doesn't work because of
> > wrong IRQs on the PowerstackII (Utah).
> 
> Which i will now fix now that i am aware of the problem. There seem to be also
> a problem on IBM prep hardware, may it be related ?

Looking at the IRQ tables in prep_pci.c it very possible. There are a
lot structures which have a lot of low numbered slots initialised to 0.
Might be that its the same problem: PCI slotnumbering has changed
resulting in wrong used entries in this tables. People should look at
this particular place if they have problems like lost interrupts, kernel
output saying that a device got IRQ 0, timeouts or something like that.

> 
> > BTW: The onboard Winbond IDE chip works as well although no connector is
> > provided. You only need a little bit of soldering and adjusting the IRQ
> > of Slot 1 from 0 to 4. :-)
> 
> Ah, wondered about that, and saw the slots are not soldered. I wonder why go
> to all the trouble including a IDE chip, but not solder the connectors. Seems
> to me like peanut savings or something.

I am not sure but I think there are two versions of this machine: One
with only IDE connectors and one with only SCSI connector.
But to be honest: I don't know as well why they didn't solder all
connectors.


Sebastian Heutling