From: daniel@ffwll.ch
To: unlisted-recipients:; (no To-header on input)
Cc: "Thierry Reding" <thierry.reding@gmail.com>,
"Uwe Kleine-König" <u.kleine-koenig@pengutronix.de>,
"Lee Jones" <lee.jones@linaro.org>,
"Daniel Thompson" <daniel.thompson@linaro.org>,
"Jingoo Han" <jingoohan1@gmail.com>,
"Bartlomiej Zolnierkiewicz" <b.zolnierkie@samsung.com>,
"Heiko Stuebner" <heiko@sntech.de>,
"Rob Herring" <robh+dt@kernel.org>,
linux-pwm@vger.kernel.org, linux-fbdev@vger.kernel.org,
"Douglas Anderson" <dianders@chromium.org>,
dri-devel@lists.freedesktop.org, linux-kernel@vger.kernel.org,
"Matthias Kaehlcke" <mka@chromium.org>,
"Enric Balletbo i Serra" <enric.balletbo@collabora.com>
Subject: Re: [PATCH 2/3] backlight: pwm_bl: Artificially add 0% during interpolation
Date: Fri, 7 Aug 2020 10:21:13 +0200 [thread overview]
Message-ID: <20200807082113.GI6419@phenom.ffwll.local> (raw)
In-Reply-To: <20200720212502.2.Iab4d2192e4cf50226e0a58d58df7d90ef92713ce@changeid>
On Mon, Jul 20, 2020 at 09:25:21PM -0700, Alexandru Stan wrote:
> Some displays need the low end of the curve cropped in order to make
> them happy. In that case we still want to have the 0% point, even though
> anything between 0% and 5%(example) would be skipped.
>
> Signed-off-by: Alexandru Stan <amstan@chromium.org>
> ---
>
> drivers/video/backlight/pwm_bl.c | 8 ++++++++
> 1 file changed, 8 insertions(+)
>
> diff --git a/drivers/video/backlight/pwm_bl.c b/drivers/video/backlight/pwm_bl.c
> index 5193a72305a2..b24711ddf504 100644
> --- a/drivers/video/backlight/pwm_bl.c
> +++ b/drivers/video/backlight/pwm_bl.c
> @@ -349,6 +349,14 @@ static int pwm_backlight_parse_dt(struct device *dev,
> /* Fill in the last point, since no line starts here. */
> table[x2] = y2;
>
> + /*
> + * If we don't start at 0 yet we're increasing, assume
> + * the dts wanted to crop the low end of the range, so
> + * insert a 0 to provide a display off mode.
> + */
> + if (table[0] > 0 && table[0] < table[num_levels - 1])
> + table[0] = 0;
Isn't that what the enable/disable switch in backlights are for? There's
lots of backligh drivers (mostly the firmware variety) where setting the
backlight to 0 does not shut it off, it's just the lowest setting.
But I've not been involved in the details of these discussions.
-Daniel
> +
> /*
> * As we use interpolation lets remove current
> * brightness levels table and replace for the
> --
> 2.27.0
>
> _______________________________________________
> dri-devel mailing list
> dri-devel@lists.freedesktop.org
> https://lists.freedesktop.org/mailman/listinfo/dri-devel
--
Daniel Vetter
Software Engineer, Intel Corporation
http://blog.ffwll.ch
next prev parent reply other threads:[~2020-08-07 8:21 UTC|newest]
Thread overview: 13+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-07-21 4:25 [PATCH 0/3] PWM backlight interpolation adjustments Alexandru Stan
2020-07-21 4:25 ` [PATCH 1/3] backlight: pwm_bl: Fix interpolation Alexandru Stan
2020-09-04 11:27 ` Daniel Thompson
2020-07-21 4:25 ` [PATCH 2/3] backlight: pwm_bl: Artificially add 0% during interpolation Alexandru Stan
2020-08-07 8:21 ` daniel [this message]
2020-08-13 13:45 ` Daniel Thompson
2020-09-04 11:38 ` Daniel Thompson
2020-09-07 7:50 ` Daniel Vetter
2020-09-09 14:45 ` Daniel Thompson
2020-09-09 15:03 ` Daniel Vetter
2020-09-10 7:47 ` Daniel Vetter
2020-09-09 18:42 ` Alexandru M Stan
2020-08-05 21:04 ` [PATCH 0/3] PWM backlight interpolation adjustments Alexandru M Stan
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=20200807082113.GI6419@phenom.ffwll.local \
--to=daniel@ffwll.ch \
--cc=b.zolnierkie@samsung.com \
--cc=daniel.thompson@linaro.org \
--cc=dianders@chromium.org \
--cc=dri-devel@lists.freedesktop.org \
--cc=enric.balletbo@collabora.com \
--cc=heiko@sntech.de \
--cc=jingoohan1@gmail.com \
--cc=lee.jones@linaro.org \
--cc=linux-fbdev@vger.kernel.org \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-pwm@vger.kernel.org \
--cc=mka@chromium.org \
--cc=robh+dt@kernel.org \
--cc=thierry.reding@gmail.com \
--cc=u.kleine-koenig@pengutronix.de \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).