From: Lee Jones <lee.jones@linaro.org>
To: Matthias Kaehlcke <mka@chromium.org>
Cc: Thierry Reding <thierry.reding@gmail.com>,
Daniel Thompson <daniel.thompson@linaro.org>,
Jingoo Han <jingoohan1@gmail.com>,
Bartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com>,
linux-pwm@vger.kernel.org, dri-devel@lists.freedesktop.org,
linux-fbdev@vger.kernel.org, linux-kernel@vger.kernel.org,
Enric Balletbo i Serra <enric.balletbo@collabora.com>,
Douglas Anderson <dianders@chromium.org>,
Brian Norris <briannorris@chromium.org>,
Pavel Machek <pavel@ucw.cz>,
Jacek Anaszewski <jacek.anaszewski@gmail.com>
Subject: Re: [PATCH v3 0/4] backlight: Expose brightness curve type through sysfs
Date: Mon, 05 Aug 2019 10:37:50 +0000 [thread overview]
Message-ID: <20190805103750.GG4739@dell> (raw)
In-Reply-To: <20190725171726.GD250418@google.com>
On Thu, 25 Jul 2019, Matthias Kaehlcke wrote:
> On Thu, Jul 25, 2019 at 12:15:41PM +0100, Lee Jones wrote:
> > On Mon, 22 Jul 2019, Matthias Kaehlcke wrote:
> >
> > > On Tue, Jul 09, 2019 at 12:00:03PM -0700, Matthias Kaehlcke wrote:
> > > > Backlight brightness curves can have different shapes. The two main
> > > > types are linear and non-linear curves. The human eye doesn't
> > > > perceive linearly increasing/decreasing brightness as linear (see
> > > > also 88ba95bedb79 "backlight: pwm_bl: Compute brightness of LED
> > > > linearly to human eye"), hence many backlights use non-linear (often
> > > > logarithmic) brightness curves. The type of curve is currently opaque
> > > > to userspace, so userspace often relies on more or less reliable
> > > > heuristics (like the number of brightness levels) to decide whether
> > > > to treat a backlight device as linear or non-linear.
> > > >
> > > > Export the type of the brightness curve via a new sysfs attribute.
> > > >
> > > > Matthias Kaehlcke (4):
> > > > MAINTAINERS: Add entry for stable backlight sysfs ABI documentation
> > > > backlight: Expose brightness curve type through sysfs
> > > > backlight: pwm_bl: Set scale type for CIE 1931 curves
> > > > backlight: pwm_bl: Set scale type for brightness curves specified in
> > > > the DT
> > > >
> > > > .../ABI/testing/sysfs-class-backlight | 26 ++++++++++++++
> > > > MAINTAINERS | 2 ++
> > > > drivers/video/backlight/backlight.c | 19 ++++++++++
> > > > drivers/video/backlight/pwm_bl.c | 35 ++++++++++++++++++-
> > > > include/linux/backlight.h | 8 +++++
> > > > 5 files changed, 89 insertions(+), 1 deletion(-)
> > > > create mode 100644 Documentation/ABI/testing/sysfs-class-backlight
> > >
> > > ping, any comments on v3?
> >
> > Looks like PATCH 2/4 still needs seeing to.
>
> The patch currently doesn't have any comments.
>
> Do you see any specific things that need improvement? If so, could you
> comment on the patch?
It needs Daniel T's Ack.
--
Lee Jones [李琼斯]
Linaro Services Technical Lead
Linaro.org │ Open source software for ARM SoCs
Follow Linaro: Facebook | Twitter | Blog
prev parent reply other threads:[~2019-08-05 10:37 UTC|newest]
Thread overview: 32+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-07-09 19:00 [PATCH v3 0/4] backlight: Expose brightness curve type through sysfs Matthias Kaehlcke
2019-07-09 19:00 ` [PATCH v3 1/4] MAINTAINERS: Add entry for stable backlight sysfs ABI documentation Matthias Kaehlcke
2019-09-02 9:41 ` Lee Jones
2019-07-09 19:00 ` [PATCH v3 2/4] backlight: Expose brightness curve type through sysfs Matthias Kaehlcke
2019-08-07 20:15 ` Matthias Kaehlcke
2019-08-16 15:54 ` Daniel Thompson
2019-08-16 17:53 ` Matthias Kaehlcke
2019-08-19 10:02 ` Daniel Thompson
2019-08-19 18:50 ` Matthias Kaehlcke
2019-08-20 13:56 ` Daniel Thompson
2019-08-27 9:44 ` Lee Jones
2019-08-29 14:09 ` Daniel Thompson
2019-08-16 16:51 ` Uwe Kleine-König
2019-08-16 17:51 ` Matthias Kaehlcke
2019-08-16 19:47 ` Uwe Kleine-König
2019-08-16 21:10 ` Matthias Kaehlcke
2019-08-19 5:46 ` Uwe Kleine-König
2019-08-19 9:50 ` Daniel Thompson
2019-08-19 10:21 ` Uwe Kleine-König
2019-08-19 11:16 ` Daniel Thompson
2019-08-19 12:29 ` Uwe Kleine-König
2019-08-20 14:49 ` Daniel Vetter
2019-08-21 14:16 ` Daniel Thompson
2019-09-02 9:41 ` Lee Jones
2019-07-09 19:00 ` [PATCH v3 3/4] backlight: pwm_bl: Set scale type for CIE 1931 curves Matthias Kaehlcke
2019-09-02 9:41 ` Lee Jones
2019-07-09 19:00 ` [PATCH v3 4/4] backlight: pwm_bl: Set scale type for brightness curves specified in the DT Matthias Kaehlcke
2019-09-02 9:42 ` Lee Jones
2019-07-22 23:59 ` [PATCH v3 0/4] backlight: Expose brightness curve type through sysfs Matthias Kaehlcke
2019-07-25 11:15 ` Lee Jones
2019-07-25 17:17 ` Matthias Kaehlcke
2019-08-05 10:37 ` Lee Jones [this message]
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