Re: [PATCH v3] irqchip/tango: Don't use incorrect irq_mask_ack callback

Florian Fainelli
2017-07-26T18:20:13Z

On 07/25/2017 06:29 AM, Måns Rullgård wrote:
> Marc Gonzalez <marc_gonzalez@sigmadesigns.com> writes:
>
>> On 25/07/2017 15:16, Måns Rullgård wrote:
>>
>>> What happened to the patch adding the proper combined function?
>>
>> It appears you're not CCed on v2.
>>
>> https://patchwork.kernel.org/patch/9859799/
>>
>> Doug wrote:
>>> Yes, you understand correctly. The irq_mask_ack method is entirely
>>> optional and I assume that is why this issue went undetected for so
>>> long; however, it is slightly more efficient to combine the functions
>>> (even if the ack is unnecessary) which is why I chose to do so for my
>>> changes to the irqchip-brcmstb-l2 driver where I first discovered this
>>> issue. How much value the improved efficiency has is certainly
>>> debatable, but interrupt handling is one area where people might care
>>> about such a small difference. As the irqchip-tango driver maintainer
>>> you are welcome to decide whether or not the irq_mask_ack method makes
>>> sense to you.
>>
>> My preference goes to leaving the irq_mask_ack callback undefined,
>> and let the irqchip framework use irq_mask and irq_ack instead.
>
> Why would you prefer the less efficient way?
>

Same question here, that does not really make sense to me.

The whole point of this patch series is to have a set of efficient and
bugfree (or nearly) helper functions that drivers can rely on, are you
saying that somehow using irq_mask_and_ack is exposing a bug in the
tango irqchip driver and using the separate functions does not expose
this bug?
--
Florian