On 09/06/16 23:56, Kevin Hilman wrote:
> Jon Hunter <jonathanh@xxxxxxxxxx> writes:
>
>> On 06/06/16 15:36, Grygorii Strashko wrote:
>>> On 06/06/2016 05:30 PM, Jon Hunter wrote:
>>>>
>>>> On 06/06/16 15:13, Grygorii Strashko wrote:
>>>>> On 06/06/2016 02:53 PM, Jon Hunter wrote:
>>>>>> Some IRQ chips may be located in a power domain outside of the CPU
>>>>>> subsystem and hence will require device specific runtime power
>>>>>> management. In order to support such IRQ chips, add a pointer for a
>>>>>> device structure to the irq_chip structure, and if this pointer is
>>>>>> populated by the IRQ chip driver and CONFIG_PM is selected in the kernel
>>>>>> configuration, then the pm_runtime_get/put APIs for this chip will be
>>>>>> called when an IRQ is requested/freed, respectively.
>>>>>>
>>>>>> Signed-off-by: Jon Hunter <jonathanh@xxxxxxxxxx>
>>>>>> Reviewed-by: Kevin Hilman <khilman@xxxxxxxxxxxx>
>>>>>> Reviewed-by: Marc Zyngier <marc.zyngier@xxxxxxx>
>>>>>> ---
>>>>>> include/linux/irq.h | 4 ++++
>>>>>> kernel/irq/chip.c | 35 +++++++++++++++++++++++++++++++++++
>>>>>> kernel/irq/internals.h | 1 +
>>>>>> kernel/irq/manage.c | 31 ++++++++++++++++++++++++++++++-
>>>>>> 4 files changed, 70 insertions(+), 1 deletion(-)
>>>>>>
>>>>>> diff --git a/include/linux/irq.h b/include/linux/irq.h
>>>>>> index 4d758a7c604a..6c92a847394d 100644
>>>>>> --- a/include/linux/irq.h
>>>>>> +++ b/include/linux/irq.h
>>>>>> @@ -315,6 +315,7 @@ static inline irq_hw_number_t irqd_to_hwirq(struct irq_data *d)
>>>>>> /**
>>>>>> * struct irq_chip - hardware interrupt chip descriptor
>>>>>> *
>>>>>> + * @parent_device: pointer to parent device for irqchip
>>>>>> * @name: name for /proc/interrupts
>>>>>> * @irq_startup: start up the interrupt (defaults to ->enable if NULL)
>>>>>> * @irq_shutdown: shut down the interrupt (defaults to ->disable if NULL)
>>>>>> @@ -354,6 +355,7 @@ static inline irq_hw_number_t irqd_to_hwirq(struct irq_data *d)
>>>>>> * @flags: chip specific flags
>>>>>> */
>>>>>> struct irq_chip {
>>>>>> + struct device *parent_device;
>>>>>> const char *name;
>>>>>> unsigned int (*irq_startup)(struct irq_data *data);
>>>>>> void (*irq_shutdown)(struct irq_data *data);
>>>>>> @@ -488,6 +490,8 @@ extern void handle_bad_irq(struct irq_desc *desc);
>>>>>> extern void handle_nested_irq(unsigned int irq);
>>>>>>
>>>>>> extern int irq_chip_compose_msi_msg(struct irq_data *data, struct msi_msg *msg);
>>>>>> +extern int irq_chip_pm_get(struct irq_data *data);
>>>>>> +extern int irq_chip_pm_put(struct irq_data *data);
>>>>>> #ifdef CONFIG_IRQ_DOMAIN_HIERARCHY
>>>>>> extern void irq_chip_enable_parent(struct irq_data *data);
>>>>>> extern void irq_chip_disable_parent(struct irq_data *data);
>>>>>> diff --git a/kernel/irq/chip.c b/kernel/irq/chip.c
>>>>>> index 2f9f2b0e79f2..b09226e895c7 100644
>>>>>> --- a/kernel/irq/chip.c
>>>>>> +++ b/kernel/irq/chip.c
>>>>>> @@ -1093,3 +1093,38 @@ int irq_chip_compose_msi_msg(struct irq_data *data, struct msi_msg *msg)
>>>>>>
>>>>>> return 0;
>>>>>> }
>>>>>> +
>>>>>> +/**
>>>>>> + * irq_chip_pm_get - Enable power for an IRQ chip
>>>>>> + * @data: Pointer to interrupt specific data
>>>>>> + *
>>>>>> + * Enable the power to the IRQ chip referenced by the interrupt data
>>>>>> + * structure.
>>>>>> + */
>>>>>> +int irq_chip_pm_get(struct irq_data *data)
>>>>>> +{
>>>>>> + int retval = 0;
>>>>>> +
>>>>>> + if (IS_ENABLED(CONFIG_PM) && data->chip->parent_device)
>>>>>> + retval = pm_runtime_get_sync(data->chip->parent_device);
>>>>>
>>>>> Sry, for the late comment - above require pm_runtime_put_noidle(data->chip->parent_device);
>>>>> in case of failure.
>>>>
>>>> No problem. Sorry, can you elaborate? I am not familiar with the
>>>> _put_noidle().
>>>>
>>>
>>> Question here in use counter - pm_runtime_get_sync() will increment usage_count
>>> always and it will not decrement it in case of failure.
>>> pm_runtime_put_noidle() expected to restore usage_count state (-1).
>>
>> Thanks was not aware of that.
>>
>> Kevin, Marc, given that you have reviewed this one, are you ok with the
>> above change Grygorii is proposing?
>
> Yes, that's the right thing to do on error.
Thanks. I have added this in V6. Please take a look and add your
reviewed-by again if all looks good.
Cheers
Jon
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