Messages in this thread | | | Date | Mon, 09 Sep 2013 06:40:58 +0200 | From | Michael Opdenacker <> | Subject | Re: [RFC][PATCH] genirq: add IRQF_NONE |
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Hi Josh,
On 09/09/2013 06:02 AM, Josh Triplett wrote: > On Mon, Sep 09, 2013 at 05:48:39AM +0200, Michael Opdenacker wrote: >> What about adding an IRQF_NONE flag as in the below patch? >> >> I'm currently working on removing the use of the deprecated >> IRQF_DISABLED flag, and frequently have to replace >> IRQF_DISABLED by 0, typically in request_irq() arguments. >> >> Using IRQF_NONE instead of 0 would make the code more readable, >> at least for people reading driver code for the first time. >> >> Would it worth it? >> >> I'm sure this kind of idea has come up many times before... >> >> Signed-off-by: Michael Opdenacker <michael.opdenacker@free-electrons.com> > I don't think it makes sense, no; it's a flags field, meant to receive a > set of flags, and 0 is the standard empty set of flags. I think > IRQF_NONE would actually reduce readability, especially for readers who > haven't seen it before, because it isn't immediately obvious that it > just corresponds to the 0 of "no flags". My first guess reading it > would be that it's some non-zero flag with some non-obvious semantic, > such as "don't actually allocate an IRQ", or something strange like Thanks for your feedback. It's true that 0 for a flag is clear enough, and that IRQF_NONE will be more confusing.
I was just thinking the IRQF_NONE would make it clearer that the corresponding argument is a flag. This way, people reading "0" wouldn't have to lookup the prototype of request_irq() to know what type of argument this is (flag, number of resources, boolean....)
So, this may be a little helpful for completely new people, but more confusing for people with a little more experience, as you explained.
I agree not to sacrifice the latter.
Thanks again,
Michael.
-- Michael Opdenacker, Free Electrons Embedded Linux, Kernel and Android engineering http://free-electrons.com +33 484 258 098
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