From: Daniel Thompson <danielt@kernel.org>
To: Michael Grzeschik <m.grzeschik@pengutronix.de>
Cc: "Uwe Kleine-König" <ukleinek@kernel.org>,
"Lee Jones" <lee@kernel.org>, "Jingoo Han" <jingoohan1@gmail.com>,
"Helge Deller" <deller@gmx.de>,
Pengutronix <kernel@pengutronix.de>,
linux-pwm@vger.kernel.org, dri-devel@lists.freedesktop.org,
linux-fbdev@vger.kernel.org, linux-kernel@vger.kernel.org
Subject: Re: [PATCH] backlight: pwm_bl: apply the initial backlight state with sane defaults
Date: Thu, 30 Oct 2025 11:51:07 +0000 [thread overview]
Message-ID: <aQNRK5ksNDMMve0x@aspen.lan> (raw)
In-Reply-To: <20250731-blpwm-v1-1-0171fd31bff9@pengutronix.de>
On Thu, Jul 31, 2025 at 10:47:18AM +0200, Michael Grzeschik wrote:
> Currently when calling pwm_apply_might_sleep in the probe routine
> the pwm will be configured with an not fully defined state.
>
> The duty_cycle is not yet set in that moment. There is a final
> backlight_update_status call that will have a properly setup state.
> However this change in the backlight can create a short flicker if the
> backlight was already preinitialised.
>
> We fix the flicker by moving the pwm_apply after the default duty_cycle
> can be calculated.
>
> Signed-off-by: Michael Grzeschik <m.grzeschik@pengutronix.de>
Reviewed-by: Daniel Thompson (RISCstar) <danielt@kernel.org>
Daniel.
next prev parent reply other threads:[~2025-10-30 11:50 UTC|newest]
Thread overview: 15+ messages / expand[flat|nested] mbox.gz Atom feed top
2025-07-31 8:47 [PATCH] backlight: pwm_bl: apply the initial backlight state with sane defaults Michael Grzeschik
2025-08-01 6:32 ` Uwe Kleine-König
2025-09-09 13:49 ` Uwe Kleine-König
2025-09-10 7:33 ` Michael Grzeschik
2025-10-30 11:51 ` Daniel Thompson [this message]
2025-11-07 8:00 ` Uwe Kleine-König
2025-11-07 14:51 ` Daniel Thompson
2025-11-07 15:48 ` Michael Grzeschik
2025-11-06 16:59 ` (subset) " Lee Jones
2025-11-14 14:09 ` Mark Brown
2025-11-18 12:52 ` Daniel Thompson
2025-11-25 8:24 ` Michael Grzeschik
2025-11-25 11:34 ` Daniel Thompson
2025-11-25 12:36 ` Mark Brown
2025-11-25 12:54 ` Lee Jones
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=aQNRK5ksNDMMve0x@aspen.lan \
--to=danielt@kernel.org \
--cc=deller@gmx.de \
--cc=dri-devel@lists.freedesktop.org \
--cc=jingoohan1@gmail.com \
--cc=kernel@pengutronix.de \
--cc=lee@kernel.org \
--cc=linux-fbdev@vger.kernel.org \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-pwm@vger.kernel.org \
--cc=m.grzeschik@pengutronix.de \
--cc=ukleinek@kernel.org \
/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 an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.