OpenPIC and the 2.6 kernel

2 messages, 2 authors, 2004-03-26 · open the first message on its own page

OpenPIC and the 2.6 kernel

From: John Whitney <hidden>
Date: 2004-03-26 22:11:02

I am working on upgrading a board support package from the 2.4.25
kernel to the 2.6.5, and I noticed that it looks like the OpenPIC
support has taken a step BACK in the 2.6 kernel.

In the 2.4 tree, openpic_hookup_cascade() exists, allowing non-8259
cascades to IRQs other than 0.  This seems to be totally missing from
the 2.6 kernel (82c59 is the ONLY supported cascade type there).  As my
board uses a custom PLD interrupt controller cascaded to an MPC107,
this is a problem.

Have I gotten the wrong repository for LinuxPPC 2.6?  I'm using
ppc.bkbits.net/linuxppc-2.5, which shows up as the 2.6.5-rc1 kernel.
If not, is there a reason this feature is now missing for the OpenPIC
driver?

Thanks,
John Whitney


** Sent via the linuxppc-dev mail list. See http://lists.linuxppc.org/

Re: OpenPIC and the 2.6 kernel

From: Tom Rini <hidden>
Date: 2004-03-26 22:18:20

On Fri, Mar 26, 2004 at 05:11:02PM -0500, John Whitney wrote:
I am working on upgrading a board support package from the 2.4.25
kernel to the 2.6.5, and I noticed that it looks like the OpenPIC
support has taken a step BACK in the 2.6 kernel.

In the 2.4 tree, openpic_hookup_cascade() exists, allowing non-8259
cascades to IRQs other than 0.  This seems to be totally missing from
the 2.6 kernel (82c59 is the ONLY supported cascade type there).  As my
board uses a custom PLD interrupt controller cascaded to an MPC107,
this is a problem.

Have I gotten the wrong repository for LinuxPPC 2.6?  I'm using
ppc.bkbits.net/linuxppc-2.5, which shows up as the 2.6.5-rc1 kernel.
If not, is there a reason this feature is now missing for the OpenPIC
driver?
This is intentional behavior.  During 2.5 development, and I think
around when openpic_hookup_cascade() went into 2.4, I asked Paul what he
thought, and he wanted something more robust I believe.  Sadly, nothing
further happened on this front.

Paul, what do you think about re-introducing openpic_hookup_cascade(irq,
name, cascade_fn(pt_regs)) in 2.6?  Or outlining a better way to handle
the problems of aribtrared controllers on OpenPIC irqs (both the custom
board described above, and Sandpoint X2 support) need something along
these lines.

--
Tom Rini
http://gate.crashing.org/~trini/

** Sent via the linuxppc-dev mail list. See http://lists.linuxppc.org/
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