Re: [PATCH V2 03/19] irqchip: crossbar: Skip some irqs from getting mapped to crossbar

From: Jason Cooper
Date: Thu Jun 12 2014 - 08:51:55 EST


On Thu, Jun 12, 2014 at 05:23:11PM +0530, Sricharan R wrote:
> From: Nishanth Menon <nm@xxxxxx>
>
> When, in the system due to varied reasons, interrupts might be unusable
> due to hardware behavior, but register maps do exist, then those interrupts
> should be skipped while mapping irq to crossbars.
>
> Signed-off-by: Nishanth Menon <nm@xxxxxx>
> Signed-off-by: Sricharan R <r.sricharan@xxxxxx>
> Signed-off-by: Tony Lindgren <tony@xxxxxxxxxxx>

Tony, have you applied these somewhere already?

> ---
> drivers/irqchip/irq-crossbar.c | 47 ++++++++++++++++++++++++++++++++++++----
> 1 file changed, 43 insertions(+), 4 deletions(-)
>
> diff --git a/drivers/irqchip/irq-crossbar.c b/drivers/irqchip/irq-crossbar.c
> index 51d4b87..847f6e3 100644
> --- a/drivers/irqchip/irq-crossbar.c
> +++ b/drivers/irqchip/irq-crossbar.c
> @@ -13,11 +13,13 @@
> #include <linux/io.h>
> #include <linux/of_address.h>
> #include <linux/of_irq.h>
> +#include <linux/of_device.h>
> #include <linux/slab.h>
> #include <linux/irqchip/arm-gic.h>
>
> #define IRQ_FREE -1
> #define IRQ_RESERVED -2
> +#define IRQ_SKIP -3
> #define GIC_IRQ_START 32
>
> /*
> @@ -34,6 +36,16 @@ struct crossbar_device {
> void (*write) (int, int);
> };
>
> +/**
> + * struct crossbar_data: Platform specific data
> + * @irqs_unused: array of irqs that cannot be used because of hw erratas
> + * @size: size of the irqs_unused array
> + */
> +struct crossbar_data {
> + const uint *irqs_unused;
> + const uint size;
> +};
> +
> static struct crossbar_device *cb;
>
> static inline void crossbar_writel(int irq_no, int cb_no)
> @@ -119,10 +131,12 @@ const struct irq_domain_ops routable_irq_domain_ops = {
> .xlate = crossbar_domain_xlate
> };
>
> -static int __init crossbar_of_init(struct device_node *node)
> +static int __init crossbar_of_init(struct device_node *node,
> + const struct crossbar_data *data)
> {
> int i, size, max, reserved = 0, entry;
> const __be32 *irqsr;
> + const int *irqsk = NULL;
>
> cb = kzalloc(sizeof(*cb), GFP_KERNEL);
>
> @@ -194,6 +208,22 @@ static int __init crossbar_of_init(struct device_node *node)
> reserved += size;
> }
>
> + /* Skip the ones marked as unused */
> + if (data) {
> + irqsk = data->irqs_unused;
> + size = data->size;
> +
> + for (i = 0; i < size; i++) {
> + entry = irqsk[i];
> +
> + if (entry > max) {
> + pr_err("Invalid skip entry\n");
> + goto err3;
> + }
> + cb->irq_map[entry] = IRQ_SKIP;
> + }
> + }
> +
> register_routable_domain_ops(&routable_irq_domain_ops);
> return 0;
>
> @@ -208,18 +238,27 @@ err1:
> return -ENOMEM;
> }
>
> +/* irq number 10 cannot be used because of hw bug */
> +int dra_irqs_unused[] = { 10 };
> +struct crossbar_data cb_dra_data = { dra_irqs_unused,
> + ARRAY_SIZE(dra_irqs_unused) };
> +
> static const struct of_device_id crossbar_match[] __initconst = {
> - { .compatible = "ti,irq-crossbar" },
> + { .compatible = "ti,irq-crossbar", .data = &cb_dra_data },
> {}
> };

This is a bug in all implementations of this IP? Or, a specific
SoC's implementation? Would this be better expressed in the dts via a
property? Can we expect future implementations to be fixed?

thx,

Jason.
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