Re: [PATCH] of/irq: of_irq_init: Call initialization function for all controllers
From: Thomas Abraham
Date: Sun Mar 25 2012 - 12:17:17 EST
On 25 March 2012 20:50, Rob Herring <robherring2@xxxxxxxxx> wrote:
> On 03/25/2012 07:38 AM, Thomas Abraham wrote:
>> The of_irq_init function stops processing the interrupt controller hierarchy
>> when there are no more interrupt controller parents identified. Though this
>> condition suffices most cases, there are cases where a interrupt controller's
>> parent controller does not participate in the initialization of the interrupt
>> hierarchy. An example of such a case is the use of a interrupt nexus node
>> by a interrupt controller node which delivers interrupts to separate interrupt
>> parent controllers.
>>
>> Instead of stopping the processing of interrupt controller hierarchy in such
>> a case, the orphan interrupt controller node's descriptor can be identified
>> and its 'logical' parent in the descriptor is set as NULL. The processing of
>> interrupt hierarchy is then restarted by looking for descriptors which have
>> a NULL interrupt parent.
>>
>> Cc: Rob Herring <rob.herring@xxxxxxxxxxx>
>> Cc: Grant Likely <grant.likely@xxxxxxxxxxxx>
>> Signed-off-by: Thomas Abraham <thomas.abraham@xxxxxxxxxx>
>> ---
>
> Wouldn't this accomplish the same thing? You just need to add the
> wakeup-map node name to your matches list.
>
>
> diff --git a/drivers/of/irq.c b/drivers/of/irq.c
> index 9cf0060..deeaf00 100644
> --- a/drivers/of/irq.c
> +++ b/drivers/of/irq.c
> @@ -416,8 +416,6 @@ void __init of_irq_init(const struct of_device_id
> *matches)
> INIT_LIST_HEAD(&intc_parent_list);
>
> for_each_matching_node(np, matches) {
> - if (!of_find_property(np, "interrupt-controller", NULL))
> - continue;
> /*
> * Here, we allocate and populate an intc_desc with the node
> * pointer, interrupt-parent device_node etc.
>
Hi Rob,
I tested with this, but the init function of wakeup controller is not
called. The following is the example nodes that I used for testing.
gic:interrupt-controller@10490000 {
compatible = "arm,cortex-a9-gic";
#interrupt-cells = <3>;
#address-cells = <0>;
#size-cells = <0>;
interrupt-controller;
cpu-offset = <0x8000>;
reg = <0x10490000 0x1000>, <0x10480000 0x100>;
};
combiner:interrupt-controller@10440000 {
compatible = "samsung,exynos4210-combiner";
#interrupt-cells = <2>;
interrupt-controller;
samsung,combiner-nr = <16>;
reg = <0x10440000 0x1000>;
interrupts = <0 0 0>, <0 1 0>, <0 2 0>, <0 3 0>,
<0 4 0>, <0 5 0>, <0 6 0>, <0 7 0>,
<0 8 0>, <0 9 0>, <0 10 0>, <0 11 0>,
<0 12 0>, <0 13 0>, <0 14 0>, <0 15 0>;
};
wakeup_eint: interrupt-controller@11400000 {
compatible = "samsung,exynos5210-wakeup-eint";
reg = <0x11400000 0x1000>;
interrupt-controller;
#interrupt-cells = <2>;
interrupt-parent = <&wakeup_map>;
interrupts = <0x0 0>, <0x1 0>, <0x2 0>, <0x3 0>,
<0x4 0>, <0x5 0>, <0x6 0>, <0x7 0>,
<0x8 0>, <0x9 0>, <0xa 0>, <0xb 0>,
<0xc 0>, <0xd 0>, <0xe 0>, <0xf 0>,
<0x10 0>;
wakeup_map: interrupt-map {
compatible = "samsung,exynos5210-wakeup-eint-map";
#interrupt-cells = <2>;
#address-cells = <0>;
#size-cells = <0>;
interrupt-map = <0x0 0 &gic 0 16 0>,
<0x1 0 &gic 0 17 0>,
<0x2 0 &gic 0 18 0>,
<0x3 0 &gic 0 19 1>,
<0x4 0 &gic 0 20 0>,
<0x5 0 &gic 0 21 1>,
<0x6 0 &gic 0 22 0>,
<0x7 0 &gic 0 23 1>,
<0x8 0 &gic 0 24 0>,
<0x9 0 &gic 0 25 1>,
<0xa 0 &gic 0 26 0>,
<0xb 0 &gic 0 27 1>,
<0xc 0 &gic 0 28 0>,
<0xd 0 &gic 0 29 1>,
<0xe 0 &gic 0 30 0>,
<0xf 0 &gic 0 31 1>,
<0x10 0 &combiner 2 4>;
};
};
And following is the match table used for testing.
static const struct of_device_id exynos4_dt_irq_match[] = {
{ .compatible = "arm,cortex-a9-gic", .data = gic_of_init, },
{ .compatible = "samsung,exynos4210-combiner",
.data = combiner_of_init, },
{ .compatible = "samsung,exynos4210-wakeup-eint-map",
.data = exynos_init_irq_eint, },
{},
};
The ' interrupt-map' map sub-node of 'interrupt-controller@11400000'
node does not have a interrupt-parent property. So it inherits it from
its parent node, which is 'interrupt-map' itself. So the parent of
wakeup-map is not gic or combiner and hence the initialization
function of wakeup controller is not called.
If a interrupt-parent property is added to 'interrupt-map' node (which
is probably not the right thing to do), and set the interrupt parent
as gic or combiner, there is a possibility that the interrupt-map is
initialized before the combiner (which is not correct since
interrupt-map uses combiner as one of its parents). But by placing
'wakeup_eint' node ahead of combiner node, this can be overcome but
relying on placement of nodes in dts file is not a reliable solution.
Thanks,
Thomas.
>
>> drivers/of/irq.c | 45 ++++++++++++++++++++++++++++++++++++++++++++-
>> 1 files changed, 44 insertions(+), 1 deletions(-)
>>
>> diff --git a/drivers/of/irq.c b/drivers/of/irq.c
>> index 9cf0060..70c6ece 100644
>> --- a/drivers/of/irq.c
>> +++ b/drivers/of/irq.c
>> @@ -400,6 +400,38 @@ struct intc_desc {
>> };
>>
>> /**
>> + * of_irq_mark_orphan_desc - Set parent as NULL for a orphan intc_desc
>> + * @intc_desc_list: the list of intc_desc to search for orphan intc_desc
>> + *
>> + * This is a helper function for the of_irq_init function and is invoked
>> + * when there are child nodes available in intc_desc_list but there are
>> + * no parent nodes in intc_parent_list. When invoked, this function
>> + * searches for a intc_desc instance that does not have a parent intc_desc
>> + * instance in intc_desc_list. The very reason of the invocation of this
>> + * function ensures that a orphan intc_desc will be found. When found, the
>> + * interrupt_parent of the orphan intc_desc is set to NULL.
>> + */
>> +static void of_irq_mark_orphan_desc(struct list_head *intc_desc_list)
>> +{
>> + struct intc_desc *desc, *temp_desc;
>> +
>> + list_for_each_entry_safe(desc, temp_desc, intc_desc_list, list) {
>> + struct intc_desc *td1, *td2;
>> + list_for_each_entry_safe(td1, td2, intc_desc_list, list) {
>> + if (desc->interrupt_parent == td1->dev)
>> + break;
>> + }
>> + if (desc->interrupt_parent == td1->dev)
>> + continue;
>> +
>> + pr_debug("%s: set interrupt_parent of 'intc_desc' with dev name"
>> + " %s as NULL\n", __func__, desc->dev->full_name);
>> + desc->interrupt_parent = NULL;
>> + return;
>> + }
>> +}
>> +
>> +/**
>> * of_irq_init - Scan and init matching interrupt controllers in DT
>> * @matches: 0 terminated array of nodes to match and init function to call
>> *
>> @@ -481,8 +513,19 @@ void __init of_irq_init(const struct of_device_id *matches)
>> /* Get the next pending parent that might have children */
>> desc = list_first_entry(&intc_parent_list, typeof(*desc), list);
>> if (list_empty(&intc_parent_list) || !desc) {
>> + /*
>> + * This has reached a point where there are children in
>> + * the intc_desc_list but no parent in intc_parent_list.
>> + * This means there is a child desc in intc_desc_list
>> + * whose parent is not one of the remaining elements of
>> + * the intc_desc_list. Such a child node is marked as
>> + * orphan (interrupt_parent is set to NULL) and the
>> + * process continues with parent set to NULL.
>> + */
>> pr_err("of_irq_init: children remain, but no parents\n");
>> - break;
>> + of_irq_mark_orphan_desc(&intc_desc_list);
>> + parent = NULL;
>> + continue;
>> }
>> list_del(&desc->list);
>> parent = desc->dev;
>
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