Hi Jon,
On 21/04/16 16:45, Jon Hunter wrote:
>
> On 20/04/16 12:03, Jon Hunter wrote:
>> Some IRQ chips, such as GPIO controllers or secondary level interrupt
>> controllers, may require require additional runtime power management
>> control to ensure they are accessible. For such IRQ chips, it makes sense
>> to enable the IRQ chip when interrupts are requested and disabled them
>> again once all interrupts have been freed.
>>
>> When mapping an IRQ, the IRQ type settings are read and then programmed.
>> The mapping of the IRQ happens before the IRQ is requested and so the
>> programming of the type settings occurs before the IRQ is requested. This
>> is a problem for IRQ chips that require additional power management
>> control because they may not be accessible yet. Therefore, when mapping
>> the IRQ, don't program the type settings, just save them and then program
>> these saved settings when the IRQ is requested (so long as if they are not
>> overridden via the call to request the IRQ).
>>
>> Add a stub function for irq_domain_free_irqs() to avoid any compilation
>> errors when CONFIG_IRQ_DOMAIN_HIERARCHY is not selected.
>>
>> Signed-off-by: Jon Hunter <jonath...@nvidia.com>
>> ---
>> include/linux/irqdomain.h | 3 +++
>> kernel/irq/irqdomain.c | 17 +++++++++++++----
>> 2 files changed, 16 insertions(+), 4 deletions(-)
>
> [snip]
>
>> - /* Set type if specified and different than the current one */
>> - if (type != IRQ_TYPE_NONE &&
>> - type != irq_get_trigger_type(virq))
>> - irq_set_irq_type(virq, type);
>> + irq_data = irq_get_irq_data(virq);
>> + if (!irq_data) {
>> + if (irq_domain_is_hierarchy(domain))
>> + irq_domain_free_irqs(virq, 1);
>> + else
>> + irq_dispose_mapping(virq);
>> + return 0;
>> + }
>> +
>> + /* Store trigger type */
>> + irqd_set_trigger_type(irq_data, type);
>> +
>
> I appear to have missed another place for saving the irq type
> which I had change in this version. Next time I will triple
> check! Should have been ...
>
>
> diff --git a/include/linux/irqdomain.h b/include/linux/irqdomain.h
> index 2aed04396210..fc66876d1965 100644
> --- a/include/linux/irqdomain.h
> +++ b/include/linux/irqdomain.h
> @@ -440,6 +440,9 @@ static inline int irq_domain_alloc_irqs(struct irq_domain
> *domain,
> return -1;
> }
>
> +static inline void irq_domain_free_irqs(unsigned int virq,
> + unsigned int nr_irqs) { }
> +
> static inline bool irq_domain_is_hierarchy(struct irq_domain *domain)
> {
> return false;
> diff --git a/kernel/irq/irqdomain.c b/kernel/irq/irqdomain.c
> index 3d6ef5527b71..46ecf5d468b2 100644
> --- a/kernel/irq/irqdomain.c
> +++ b/kernel/irq/irqdomain.c
> @@ -569,6 +569,7 @@ static void of_phandle_args_to_fwspec(struct
> of_phandle_args *irq_data,
> unsigned int irq_create_fwspec_mapping(struct irq_fwspec *fwspec)
> {
> struct irq_domain *domain;
> + struct irq_data *irq_data;
> irq_hw_number_t hwirq;
> unsigned int type = IRQ_TYPE_NONE;
> int virq;
> @@ -619,7 +620,11 @@ unsigned int irq_create_fwspec_mapping(struct irq_fwspec
> *fwspec)
> * it now and return the interrupt number.
> */
> if (IRQ_TYPE_NONE == irq_get_trigger_type(virq)) {
> - irq_set_irq_type(virq, type);
> + irq_data = irq_get_irq_data(virq);
> + if (!irq_data)
> + return 0;
Can you point out in which circumstances irq_data can be NULL? If we can
lookup the interrupt in the domain, it'd better exist somewhere. Or am I
missing something obvious?
Thanks,
M.
--
Jazz is not dead. It just smells funny...
