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Groups > linux.kernel > #1420708
| From | Marc Zyngier <marc.zyngier@arm.com> |
|---|---|
| Newsgroups | linux.kernel |
| Subject | Re: [PATCH V6 2/9] genirq: Look-up trigger type if not specified by caller |
| Date | 2016-06-13 12:50 +0200 |
| Message-ID | <rJxBn-56h-7@gated-at.bofh.it> (permalink) |
| References | <rHqXn-4lt-15@gated-at.bofh.it> <rHqXo-4lt-51@gated-at.bofh.it> |
| Organization | ARM Ltd |
On 07/06/16 16:12, Jon Hunter wrote:
> For some devices the IRQ trigger type for a device is read from
> firmware, such as device-tree. The IRQ trigger type is typically read
> when the mapping for IRQ is created, which is before the IRQ is
> requested. Hence, the IRQ trigger type is programmed when mapping the
> IRQ and not when requesting the IRQ.
>
> Although this works for most cases, in order to support IRQ chips which
> require runtime power management, which may not be accessible prior
> to requesting the IRQ, it is desirable to look-up the IRQ trigger type
> when it is requested. Therefore, if the IRQ trigger type is not
> specified when __setup_irq() is called, look-up the saved IRQ trigger
> type. This will allow us to defer the programming of the trigger type
> from when the IRQ is mapped to when it is actually requested.
>
> Signed-off-by: Jon Hunter <jonathanh@nvidia.com>
> Reviewed-by: Marc Zyngier <marc.zyngier@arm.com>
> ---
> kernel/irq/manage.c | 7 +++++++
> 1 file changed, 7 insertions(+)
>
> diff --git a/kernel/irq/manage.c b/kernel/irq/manage.c
> index ef0bc02c3a70..eaedeb74b49d 100644
> --- a/kernel/irq/manage.c
> +++ b/kernel/irq/manage.c
> @@ -1117,6 +1117,13 @@ __setup_irq(unsigned int irq, struct irq_desc *desc, struct irqaction *new)
> new->irq = irq;
>
> /*
> + * If the trigger type is not specified by the caller,
> + * then use the default for this interrupt.
> + */
> + if (!(new->flags & IRQF_TRIGGER_MASK))
> + new->flags |= irqd_get_trigger_type(&desc->irq_data);
> +
> + /*
> * Check whether the interrupt nests into another interrupt
> * thread.
> */
>
I've added the following patch to the queue, in order to deal with
percpu interrupts that were not handled by this patch:
diff --git a/kernel/irq/manage.c b/kernel/irq/manage.c
index f8fd1fb..00cfc85 100644
--- a/kernel/irq/manage.c
+++ b/kernel/irq/manage.c
@@ -1751,7 +1751,14 @@ void enable_percpu_irq(unsigned int irq, unsigned int type)
if (!desc)
return;
+ /*
+ * If the trigger type is not specified by the caller, then
+ * use the default for this interrupt.
+ */
type &= IRQ_TYPE_SENSE_MASK;
+ if (type == IRQ_TYPE_NONE)
+ type = irqd_get_trigger_type(&desc->irq_data);
+
if (type != IRQ_TYPE_NONE) {
int ret;
Thanks,
M.
--
Jazz is not dead. It just smells funny...
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Re: [PATCH V6 2/9] genirq: Look-up trigger type if not specified by caller Marc Zyngier <marc.zyngier@arm.com> - 2016-06-13 12:50 +0200
Re: [PATCH V6 2/9] genirq: Look-up trigger type if not specified by caller Jon Hunter <jonathanh@nvidia.com> - 2016-06-13 13:10 +0200
Re: [PATCH V6 2/9] genirq: Look-up trigger type if not specified by caller Marc Zyngier <marc.zyngier@arm.com> - 2016-06-13 14:10 +0200
Re: [PATCH V6 2/9] genirq: Look-up trigger type if not specified by caller Jon Hunter <jonathanh@nvidia.com> - 2016-06-13 14:30 +0200
Re: [PATCH V6 2/9] genirq: Look-up trigger type if not specified by caller Marc Zyngier <marc.zyngier@arm.com> - 2016-06-13 14:40 +0200
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