From: Vladimir Oltean <olteanv@gmail.com>
To: Andrew Lunn <andrew@lunn.ch>
Cc: Chen Minqiang <ptpt52@gmail.com>, Rob Herring <robh@kernel.org>,
Krzysztof Kozlowski <krzk+dt@kernel.org>,
Conor Dooley <conor+dt@kernel.org>,
Matthias Brugger <matthias.bgg@gmail.com>,
AngeloGioacchino Del Regno
<angelogioacchino.delregno@collabora.com>,
"Chester A. Unal" <chester.a.unal@arinc9.com>,
Daniel Golle <daniel@makrotopia.org>,
DENG Qingfang <dqfext@gmail.com>,
Sean Wang <sean.wang@mediatek.com>,
linux-kernel@vger.kernel.org,
linux-arm-kernel@lists.infradead.org,
linux-mediatek@lists.infradead.org, netdev@vger.kernel.org
Subject: Re: [PATCH v3 2/2] net: dsa: mt7530: Use GPIO polarity to generate correct reset sequence
Date: Sun, 30 Nov 2025 10:07:31 +0200 [thread overview]
Message-ID: <20251130080731.ty2dlxaypxvodxiw@skbuf> (raw)
In-Reply-To: <0675b35f-217d-4261-9e3f-2eb24753d43c@lunn.ch>
On Sun, Nov 30, 2025 at 02:11:05AM +0100, Andrew Lunn wrote:
> > - gpiod_set_value_cansleep(priv->reset, 0);
> > + int is_active_low = !!gpiod_is_active_low(priv->reset);
> > + gpiod_set_value_cansleep(priv->reset, is_active_low);
>
> I think you did not correctly understand what Russell said. You pass
> the logical value to gpiod_set_value(). If the GPIO has been marked as
> active LOW, the GPIO core will invert the logical values to the raw
> value. You should not be using gpiod_is_active_low().
>
> But as i said to the previous patch, i would just leave everything as
> it is, except document the issue.
>
> Andrew
>
It was my suggestion to do it like this (but I don't understand why I'm
again not in CC).
We _know_ that the reset pin of the switch should be active low. So by
using gpiod_is_active_low(), we can determine whether the device tree is
wrong or not, and we can work with a wrong device tree too (just invert
the logical values).
next prev parent reply other threads:[~2025-11-30 8:07 UTC|newest]
Thread overview: 28+ messages / expand[flat|nested] mbox.gz Atom feed top
2025-11-29 23:46 [PATCH v3 1/2] ARM64: dts: mediatek: fix MT7531 reset GPIO polarity on multiple boards Chen Minqiang
2025-11-29 23:46 ` [PATCH v3 2/2] net: dsa: mt7530: Use GPIO polarity to generate correct reset sequence Chen Minqiang
2025-11-30 1:11 ` Andrew Lunn
2025-11-30 8:07 ` Vladimir Oltean [this message]
2025-11-30 20:17 ` Andrew Lunn
2025-12-01 7:48 ` Krzysztof Kozlowski
2025-12-02 11:52 ` Frank Wunderlich
2025-12-02 12:20 ` Daniel Golle
2025-12-04 13:16 ` Vladimir Oltean
2025-12-04 13:50 ` Daniel Golle
2025-12-04 15:45 ` Vladimir Oltean
2025-12-04 14:49 ` Krzysztof Kozlowski
2025-12-04 16:02 ` Vladimir Oltean
2025-12-04 16:48 ` Krzysztof Kozlowski
2025-12-04 17:11 ` Vladimir Oltean
2025-12-04 17:23 ` Krzysztof Kozlowski
2025-12-04 17:32 ` Krzysztof Kozlowski
2025-12-04 20:47 ` Russell King (Oracle)
2025-12-04 17:45 ` Russell King (Oracle)
2025-12-04 18:21 ` Vladimir Oltean
2025-12-04 15:22 ` Andrew Lunn
2025-12-04 15:37 ` Vladimir Oltean
2025-12-04 15:50 ` Andrew Lunn
2025-12-04 15:52 ` Krzysztof Kozlowski
2025-12-04 16:33 ` Vladimir Oltean
2025-11-30 8:22 ` Vladimir Oltean
2025-12-01 7:50 ` Krzysztof Kozlowski
2025-11-30 1:00 ` [PATCH v3 1/2] ARM64: dts: mediatek: fix MT7531 reset GPIO polarity on multiple boards Andrew Lunn
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=20251130080731.ty2dlxaypxvodxiw@skbuf \
--to=olteanv@gmail.com \
--cc=andrew@lunn.ch \
--cc=angelogioacchino.delregno@collabora.com \
--cc=chester.a.unal@arinc9.com \
--cc=conor+dt@kernel.org \
--cc=daniel@makrotopia.org \
--cc=dqfext@gmail.com \
--cc=krzk+dt@kernel.org \
--cc=linux-arm-kernel@lists.infradead.org \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-mediatek@lists.infradead.org \
--cc=matthias.bgg@gmail.com \
--cc=netdev@vger.kernel.org \
--cc=ptpt52@gmail.com \
--cc=robh@kernel.org \
--cc=sean.wang@mediatek.com \
/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