Re: [PATCH v5 2/3] i2c: iproc: Add Broadcom iProc I2C Driver

[Arend van Spriel]

On 01/18/15 12:56, Uwe Kleine-König wrote:
> Hello,
>
> On Sun, Jan 18, 2015 at 12:46:51PM +0100, Arend van Spriel wrote:
> > On 01/18/15 12:17, Uwe Kleine-König wrote:
> > > Hello Wolfram,
> > >
> > > On Sun, Jan 18, 2015 at 12:06:58PM +0100, Wolfram Sang wrote:
> > > > On Sun, Jan 18, 2015 at 10:47:41AM +0100, Uwe Kleine-König wrote:
> > > > > On Sun, Jan 18, 2015 at 10:14:04AM +0100, Arend van Spriel wrote:
> > > > > > On 01/17/15 00:42, Ray Jui wrote:
> > > > > > > +	complete_all(&iproc_i2c->done);
> > > > > >
> > > > > > Looking over this code it seems to me there is always a single
> > > > > > process waiting for iproc_i2c->done to complete. So using complete()
> > > > > > here would suffice.
> > > > > Yeah, there is always only a single thread waiting. That means both
> > > > > complete and complete_all are suitable. AFAIK there is no reason to pick
> > > > > one over the other in this case.
> > > >
> > > > Clarity?
> > > And which do you consider more clear? complete_all might result in the
> > > question: "Is there>1 waiter?" and complete might yield to "What about
> > > the other waiters?". If you already know there is only one, both are on
> > > par on clarity. Might only be me?! I don't care much.
> >
> > Maybe it is me, but it is not about questions but it is about
> > implicit statements that the code makes (or reader derives from it).
> > When using complete_all you indicate to the reader "there can be
> > more than one waiter". When using complete it indicates "there is
> > only one waiter". If those statements are not true that is a code
> No, complete works just fine in the presence of>1 waiter. It just wakes
> a single waiter and all others continue to wait.

Yes. Agree.

> That is, for single-waiter situations there is no semantic difference
> between complete and complete_all. But there is a difference for
> multi-waiter queues.

Indeed.

> I think this is just a matter of your POV in the single-waiter
> situation: complete might be intuitive because you just completed a
> single task and complete_all might be intuitive because it signals
> "I'm completely done, there is noone waiting for me any more.".

Ok. Let's leave it to the author's intuition or to say it differently 
"sorry for the noise" ;-)

Regards,
Arend

> Best regards
> Uwe

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