Re: pSeries boot failure due to wrong interrupt controller

On Fri, 2015-06-26 at 12:54 -0500, Jeremy Linton wrote:

Ping? Anyone?

I'm adding ppc-dev to see if anyone there is interested in picking up the patch..

Ah I missed that completely. From your discussion, it looks correct,
I'll see if I can find a machine to test, however I think we dropped
support for POWER3 so it might be non-trivial to do so.

And yes, when there is no map, the parent should be the interrupt-parent
with a fallback to the parent node if that doesn't exist.

Cheers,
Ben.

Thanks,
	Jeremy


Ok so I messed up the formatting a little and was lazy and didn't checkpatch it
cause I mean, it was 1 line! If someone wants it resent I will do so.





On 6/23/2015 8:42 AM, Rob Herring wrote:

quoted

+Grant

On Mon, Jun 22, 2015 at 2:44 PM, Jeremy Linton [off-list ref] wrote:

quoted

The OF IRQ logic was refactored a while back, and it appears that it
broke the case where a device doesn't have an interrupt-map
(legacy/ISA platform peripherals). In particular on the older pSeries
platforms the console serial port (keyboard/etc) is attached via a
Winbond super I/O controller. With the refactored logic
of_irq_parse_raw() returns with the out_irq->np pointing at the bus,
rather than the interrupt controller. This results in the platform
logic getting confused about the appropriate interrupt host, and in
ics_rtas_host_match() it doesn't match "chrp,iic" and the xics takes
over and tries to use RTAS to map the interrupt. RTAS then crashes the
machine.

This tweaks the "-> no map, getting parent" behavior to behave as
before, and the machine boots.

I think the real question is why doesn't of_irq_find_parent return the
interrupt controller node instead of the bus node.

While I think this fix is correct, I think of_irq_parse_raw should be
a nop in the case of no interrupt-map.

Rob

quoted

Thanks

Signed-off-by: Jeremy Linton <redacted>

diff --git a/drivers/of/irq.c b/drivers/of/irq.c
index 1a79806..78b4161b 100644
--- a/drivers/of/irq.c
+++ b/drivers/of/irq.c

@@ -252,7 +252,6 @@ int of_irq_parse_raw(const __be32 *addr, struct

of_phandle_args *out_irq)
                 * Successfully parsed an interrrupt-map translation; copy new
                 * interrupt specifier into the out_irq structure
                 */
-               out_irq->np = newpar;

                match_array = imap - newaddrsize - newintsize;
                for (i = 0; i < newintsize; i++)

@@ -262,6 +261,7 @@ int of_irq_parse_raw(const __be32 *addr, struct

of_phandle_args *out_irq)

        skiplevel:
                /* Iterate again with new parent */
+               out_irq->np = newpar;
                pr_debug(" -> new parent: %s\n", of_node_full_name(newpar));
                of_node_put(ipar);
                ipar = newpar;