Re: [PATCH 3/5] leds: Rename brightness_set_sync op to brightness_set_blocking

[Jacek Anaszewski]

On 09/23/2015 10:36 AM, Jacek Anaszewski wrote:
> On 09/22/2015 08:54 PM, Andrew Lunn wrote:
> > On Wed, Sep 16, 2015 at 12:47:42PM +0200, Jacek Anaszewski wrote:
> > > The initial purpose of brightness_set_sync op, introduced along with
> > > the LED flash class extension, was to add a means for setting torch LED
> > > brightness as soon as possible, which couldn't have been guaranteed by
> > > brightness_set op. This patch renames the op to brightness_set_blocking,
> > > which describes its purpose in a more generic way, and is beneficial
> > > in view of the prospective changes in the core related to using
> > > LED core's set_brightness_work for setting brightness for LED class
> > > drivers that can sleep or use delays while setting brightness.
> >
> > ...
> >
> > > -    /*
> > > -     * Set LED brightness level immediately - it can block the
> > > caller for
> > > -     * the time required for accessing a LED device register.
> > > -     */
> > > -    int        (*brightness_set_sync)(struct led_classdev *led_cdev,
> > > -                    enum led_brightness brightness);
> > > +    /* Can sleep or use delays */
> > > +    int (*brightness_set_blocking)(struct led_classdev *led_cdev,
> >
> > I'm no expert when it comes to flash photography with digital
> > cameras.
>
> This op is now not specific to flash LEDs. The last sentence in the
> commit message explains this, but now I see that it is too long.
> Let's change it to:
>
> "This patch renames the op to brightness_set_blocking,
> which describes its purpose in a more generic way. It is beneficial
> in view of the prospective changes in the LED core, aiming at removing
> the need for using work queues in LED class drivers that can sleep
> or use delays while setting brightness."
>
> > But to me the old comment seems better.
>
> I changed it to highlight the essence of how it differs from
> brightness_set.
>
> > Doesn't the caller
> > want to know the flash is now giving out light?
>
> We have strobe_get op for this, but it is in led-class-flash extension.
> This is irrelevant here.

I focused myself on flash mode of flash LED, but you asked
probably about brightness in torch mode, which can be obtained
with brightness_get op, if implemented by the driver.


--
Best Regards,
Jacek Anaszewski
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