[PATCH RFC] Revert "of/irq: Mark initialised interrupt controllers as populated"

[Javier Martinez Canillas]

Hello Rob,

On Sun, Aug 14, 2016 at 1:32 PM, Rob Herring <robh+dt at kernel.org> wrote:
> On Sat, Aug 13, 2016 at 4:45 AM, Russell King
> <rmk+kernel at armlinux.org.uk> wrote:
>> This reverts commit 15cc2ed6dcf91a8658e084be4e140147161819d7, which
>> causes a regression with iMX6 power domains.  iMX6 GPC contains both an
>> interrupt controller and power domains.  The iMX6 GPC code is setup to
>> register an interrupt controller using IRQCHIP_DECLARE(), but then to
>> register the power domains using the platform device.
>>
>> This commit prevents the platform device being created, thereby breaking
>> iMX6 power domain support.
>>

That commit also broke Exynos platforms since several devices are not
created (GIC, Exynos combiner and PMU system controller for
Exynos5420/5422/5800).

>> Signed-off-by: Russell King <rmk+kernel at armlinux.org.uk>
>> ---
>> Please argue amongst yourselves about how to fix this regression caused
>> by this commit...
>
> There's already a fix for this in my tree and -next. I will be sending
> to Linus soon.
>

I guess you mean patch "[1/2] of/irq: Mark interrupt controllers as
populated before initialisation" [0] ?

Even with that patch on top of v4.8-rc2, things don't work for me. I
needed to revert setting the OF_POPULATED flag in of_irq_init for
things to work:

diff --git a/drivers/of/irq.c b/drivers/of/irq.c
index a2e68f740eda..5f9adc6c06e7 100644
--- a/drivers/of/irq.c
+++ b/drivers/of/irq.c
@@ -544,7 +544,7 @@ void __init of_irq_init(const struct of_device_id *matches)

                        list_del(&desc->list);

-                       of_node_set_flag(desc->dev, OF_POPULATED);
+                       //of_node_set_flag(desc->dev, OF_POPULATED);

                        pr_debug("of_irq_init: init %s (%p), parent %p\n",
                                 desc->dev->full_name,

I noticed that Philipp also sent a patch to clear that flag in
arch/arm/mach-imx/gpc.c [1]. I guess the same is needed in the drivers
for the devices that are not created for Exynos?

If that's the case, then I think that's more safe to revert Jon's
commit for now since is too risky for the -rc cycle and more platforms
may be affected.

[0]: https://patchwork.kernel.org/patch/9271361/
[1]: https://patchwork.kernel.org/patch/9271345/

> Rob
>

Best regards,
Javier