On Thu, Jan 13, 2022 at 01:42:57PM -0800, Florian Fainelli wrote: > > > On 1/13/2022 11:43 AM, Uwe Kleine-König wrote: > > The subsystems regulator, clk and gpio have the concept of a dummy > > resource. For regulator, clk and gpio there is a semantic difference > > between the regular _get() function and the _get_optional() variant. > > (One might return the dummy resource, the other won't. Unfortunately > > which one implements which isn't the same for these three.) The > > difference between platform_get_irq() and platform_get_irq_optional() is > > only that the former might emit an error message and the later won't. > > > > To prevent people's expectations that there is a semantic difference > > between these too, rename platform_get_irq_optional() to > > platform_get_irq_silent() to make the actual difference more obvious. > > > > The #define for the old name can and should be removed once all patches > > currently in flux still relying on platform_get_irq_optional() are > > fixed. > > > > Signed-off-by: Uwe Kleine-König <u.kleine-koenig@xxxxxxxxxxxxxx> > > --- > > Hello, > > > > On Thu, Jan 13, 2022 at 02:45:30PM +0000, Mark Brown wrote: > > > On Thu, Jan 13, 2022 at 12:08:31PM +0100, Uwe Kleine-König wrote: > > > > > > > This is all very unfortunate. In my eyes b) is the most sensible > > > > sense, but the past showed that we don't agree here. (The most annoying > > > > part of regulator_get is the warning that is emitted that regularily > > > > makes customers ask what happens here and if this is fixable.) > > > > > > Fortunately it can be fixed, and it's safer to clearly specify things. > > > The prints are there because when the description is wrong enough to > > > cause things to blow up we can fail to boot or run messily and > > > forgetting to describe some supplies (or typoing so they haven't done > > > that) and people were having a hard time figuring out what might've > > > happened. > > > > Yes, that's right. I sent a patch for such a warning in 2019 and pinged > > occationally. Still waiting for it to be merged :-\ > > (https://lore.kernel.org/r/20190625100412.11815-1-u.kleine-koenig@xxxxxxxxxxxxxx) > > > > > > I think at least c) is easy to resolve because > > > > platform_get_irq_optional() isn't that old yet and mechanically > > > > replacing it by platform_get_irq_silent() should be easy and safe. > > > > And this is orthogonal to the discussion if -ENOXIO is a sensible return > > > > value and if it's as easy as it could be to work with errors on irq > > > > lookups. > > > > > > It'd certainly be good to name anything that doesn't correspond to one > > > of the existing semantics for the API (!) something different rather > > > than adding yet another potentially overloaded meaning. > > > > It seems we're (at least) three who agree about this. Here is a patch > > fixing the name. > > From an API naming perspective this does not make much sense anymore with > the name chosen, it is understood that whent he function is called > platform_get_irq_optional(), optional applies to the IRQ. An optional IRQ is > something people can reason about because it makes sense. The problem I see is that the semantic is different to the other available *_get_optional() functions. And this isn't fixable for irqs. So better don't use that naming scheme. > What is a a "silent" IRQ however? It does not apply to the object it is > trying to fetch to anymore, but to the message that may not be printed in > case the resource failed to be obtained, because said resource is optional. > Woah, that's quite a stretch. I'm surprised that the semantic isn't obvious, but ok, I can accept that.Can you maek a constructive suggestion here? What name pair would you choose for the two functions functions under discussion? (BTW, my favourite would be that platform_get_irq() doesn't emit an error message and the caller is reliable for emitting that. But I think it's too late for this approach.) > Following the discussion and original 2 patches set from Sergey, it is not > entirely clear to me anymore what is it that we are trying to fix. (I think) Sergey's focus is: platform_get_irq_optional() returning -ENXIO is ugly, other functions return -ENOENT and other *_get_optional() functions return NULL for "This resource doesn't exist". So let's return 0 in this case. My focus is: There cannot be an "optional irq" where the driver doesn't have to care if the irq actually exist or not. So the pattern with *_get_optional() isn't sensible for irqs and if changing the returned value meaning "This resource doesn't exist" is sensible for platform_get_irq_optional(), I claim it's sensible for platform_get_irq(), too. So the semantic difference between platform_get_irq() and platform_get_irq_optional() is only that one emits an error message and the other doesn't. So this function pair should use a different naming than get + get_optional as this naming evokes expectations that must be wrong as there cannot be a dummy irq value. > I nearly forgot, I would paint it blue, sky blue, not navy blue, not light > blue ;) no way. green is the ultimate blue for platform_get_irq() :-) Best regards Uwe -- Pengutronix e.K. | Uwe Kleine-König | Industrial Linux Solutions | https://www.pengutronix.de/ |
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