+Grant
On Mon, Jun 22, 2015 at 2:44 PM, Jeremy Linton <lintonrjeremy@xxxxxxxxx> wrote:
> 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
>
> Thanks
>
> Signed-off-by: Jeremy Linton <lintonrjeremy@xxxxxxxxx>
>
>
> 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;
> --
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