[PATCH] of: irq: use of_irq_get() in of_irq_to_resource()

[Rob Herring]

On Tue, May 16, 2017 at 02:09:04PM +0200, Thomas Petazzoni wrote:
> of_irq_to_resource() currently uses irq_of_parse_and_map() to
> translate a DT interrupt specification into a Linux virtual interrupt
> number. While this works in most cases, irq_of_parse_and_map() doesn't
> properly handle the case where the interrupt controller is not yet
> available (due to deferred probing for example).
> 
> So instead, use of_irq_get(), which is implemented exactly like
> irq_of_parse_and_map(), with the exception that if the interrupt
> controller is not yet available, it returns -EPROBE_DEFER. Obviously,
> we also handle this error and bail out from of_irq_to_resource() when
> of_irq_get() returns an error.
> 
> This allows to avoid silly error messages at boot time caused by
> irq_create_of_mapping() when the interrupt controller is not
> available:
> 
> [    0.153168] irq: no irq domain found for /ap806/config-space at f0000000/interrupt-controller at 3f0100 !
> [    0.154041] irq: no irq domain found for /cp110-master/config-space at f2000000/interrupt-controller at 1e0000 !
> [    0.154124] irq: no irq domain found for /cp110-master/config-space at f2000000/interrupt-controller at 1e0000 !
> [    0.154207] irq: no irq domain found for /cp110-master/config-space at f2000000/interrupt-controller at 1e0000 !
> [    0.154437] irq: no irq domain found for /cp110-master/config-space at f2000000/interrupt-controller at 1e0000 !
> [    0.154518] irq: no irq domain found for /cp110-master/config-space at f2000000/interrupt-controller at 1e0000 !
> 
> Signed-off-by: Thomas Petazzoni <thomas.petazzoni at free-electrons.com>
> ---
>  drivers/of/irq.c | 5 ++++-
>  1 file changed, 4 insertions(+), 1 deletion(-)

Applied.

BTW, the reason we have both irq_of_parse_and_map and of_irq_get is 
irq_of_parse_and_map returns NO_IRQ or an irq. Adding an errno may not 
get handled correctly and it's not as simple as auditing the call sites.

Rob