From: Wolfram Sang <wsa+renesas@sang-engineering.com>
To: Chen-Yu Tsai <wenst@chromium.org>
Cc: Mark Brown <broonie@kernel.org>,
Matthias Brugger <matthias.bgg@gmail.com>,
AngeloGioacchino Del Regno
<angelogioacchino.delregno@collabora.com>,
Dmitry Torokhov <dmitry.torokhov@gmail.com>,
Jiri Kosina <jikos@kernel.org>,
Andi Shyti <andi.shyti@kernel.org>,
Benson Leung <bleung@chromium.org>,
Tzung-Bi Shih <tzungbi@kernel.org>,
linux-mediatek@lists.infradead.org, devicetree@vger.kernel.org,
linux-arm-kernel@lists.infradead.org,
chrome-platform@lists.linux.dev, linux-input@vger.kernel.org,
linux-i2c@vger.kernel.org, linux-kernel@vger.kernel.org
Subject: Re: [PATCH v7 4/8] i2c: of-prober: skip post-power-on delay if powered on sufficiently long
Date: Tue, 10 Nov 2026 11:24:24 +0100 [thread overview]
Message-ID: <avLw2AiqcnO9Blun@shikoro> (raw)
In-Reply-To: <20261103043734.2179858-5-wenst@chromium.org>
On Tue, Nov 03, 2026 at 12:37:28PM +0800, Chen-Yu Tsai wrote:
> On some devices the I2C component is powered from an always-on power
> rail, or the power rail has been left on by either POR defaults or
> the bootloader. By the time the prober probes the device, the device
> most certainly has finished initializing and can respond. There is no
> need for the delay.
>
> In such designs, the system integrators tend to work around the delay
> to avoid the boot time penalty by simply omitting it from the device
> tree and the component prober. This is undesired, as the device tree
> is not fully describing the hardware.
>
> Switch to the new regulator_enable_and_wait() function that makes sure
> a certain amount of time has passed since the regulator supply was
> actually enabled.
>
> Signed-off-by: Chen-Yu Tsai <wenst@chromium.org>
Acked-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
@Andi: Chen-Yu is the maintainer of the of-prober, so I suggest these
changes just go in together with this series.
next prev parent reply other threads:[~2026-11-10 10:24 UTC|newest]
Thread overview: 16+ messages / expand[flat|nested] mbox.gz Atom feed top
2026-11-03 4:37 [PATCH v7 0/8] arm64: mediatek: Chromebook trackpad supply fixes Chen-Yu Tsai
2026-11-03 4:37 ` [PATCH v7 1/8] regulator: core: Add "enable and wait" functions Chen-Yu Tsai
2026-11-03 5:11 ` sashiko-bot
2026-11-03 4:37 ` [PATCH v7 2/8] Input: elan_i2c - Wait for initialization after enabling regulator supply Chen-Yu Tsai
2026-11-03 4:37 ` [PATCH v7 3/8] HID: i2c-hid-of: skip post-power-on delay if powered on sufficiently long Chen-Yu Tsai
2026-11-03 4:52 ` sashiko-bot
2026-11-03 4:37 ` [PATCH v7 4/8] i2c: of-prober: " Chen-Yu Tsai
2026-11-10 10:24 ` Wolfram Sang [this message]
2026-11-03 4:37 ` [PATCH v7 5/8] i2c: of-prober: Let cleanup op know if a device was found Chen-Yu Tsai
2026-11-10 10:24 ` Wolfram Sang
2026-11-03 4:37 ` [PATCH v7 6/8] i2c: of-prober: Defer regulator_disable() on successful probe in simple helper Chen-Yu Tsai
2026-11-10 10:24 ` Wolfram Sang
2026-11-03 4:37 ` [PATCH v7 7/8] arm64: dts: mediatek: mt8173-elm-hana: Unmark trackpad supply as always-on Chen-Yu Tsai
2026-11-03 4:37 ` [PATCH v7 8/8] arm64: dts: mediatek: mt8192-asurada-spherion: Add Synaptics trackpad's supply Chen-Yu Tsai
2026-11-07 16:43 ` (subset) [PATCH v7 0/8] arm64: mediatek: Chromebook trackpad supply fixes Mark Brown
2026-11-09 5:41 ` Chen-Yu Tsai
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=avLw2AiqcnO9Blun@shikoro \
--to=wsa+renesas@sang-engineering.com \
--cc=andi.shyti@kernel.org \
--cc=angelogioacchino.delregno@collabora.com \
--cc=bleung@chromium.org \
--cc=broonie@kernel.org \
--cc=chrome-platform@lists.linux.dev \
--cc=devicetree@vger.kernel.org \
--cc=dmitry.torokhov@gmail.com \
--cc=jikos@kernel.org \
--cc=linux-arm-kernel@lists.infradead.org \
--cc=linux-i2c@vger.kernel.org \
--cc=linux-input@vger.kernel.org \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-mediatek@lists.infradead.org \
--cc=matthias.bgg@gmail.com \
--cc=tzungbi@kernel.org \
--cc=wenst@chromium.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.