Re: [PATCH v2 4/5] gpiolib: cdev: reduce locking in gpio_desc_to_lineinfo()

From: Andy Shevchenko
Date: Thu Dec 14 2023 - 10:50:27 EST


On Thu, Dec 14, 2023 at 11:34:44PM +0800, Kent Gibson wrote:
> On Thu, Dec 14, 2023 at 05:27:29PM +0200, Andy Shevchenko wrote:
> > On Thu, Dec 14, 2023 at 11:19:01PM +0800, Kent Gibson wrote:
> > > On Thu, Dec 14, 2023 at 05:10:23PM +0200, Andy Shevchenko wrote:
> > > > On Thu, Dec 14, 2023 at 05:58:13PM +0800, Kent Gibson wrote:

...

> > > > > - spin_lock_irqsave(&gpio_lock, flags);
> > > >
> > > > Shouldn't this be covered by patch 1 (I mean conversion to scoped_guard()
> > > > instead of spinlock)?
> > >
> > > Read the cover letter.
> > > Doing that made the change larger, as flags gets removed then restored.
> > > I had also thought the flag tests would get indented then unindented, but
> > > if we use guard() the indentation should remain unchanged.
> >
> > I'm fine with that as I pointed out (have you received that mail? I had
> > problems with my mail server) the dflags is better semantically, so restoration
> > with _different_ name is fine.
>
> I have noted that some of your replies have been delayed, and I can't be sure
> of what I might not've received. I can't say I've seen one that mentions the
> dflags name being preferable.
>
> I prefer the plain flags name, if there is only one flag variable in the
> function.

I pointed out that lflags / dflags is kinda idiomatic internally to gpiolib*
code base. Using flags might feel misleading and otherwise will hint about
semantics of the variable. That said, I prefer it being named dflags.

--
With Best Regards,
Andy Shevchenko