netdev.vger.kernel.org archive mirror
 help / color / mirror / Atom feed
From: Russell King - ARM Linux admin <linux@armlinux.org.uk>
To: DENG Qingfang <dqfext@gmail.com>
Cc: "Andrew Lunn" <andrew@lunn.ch>,
	"Vivien Didelot" <vivien.didelot@gmail.com>,
	"Florian Fainelli" <f.fainelli@gmail.com>,
	"Vladimir Oltean" <olteanv@gmail.com>,
	"David S. Miller" <davem@davemloft.net>,
	"Jakub Kicinski" <kuba@kernel.org>,
	"Rob Herring" <robh+dt@kernel.org>,
	"Matthias Brugger" <matthias.bgg@gmail.com>,
	"Sean Wang" <sean.wang@mediatek.com>,
	"Landen Chao" <Landen.Chao@mediatek.com>,
	"Philipp Zabel" <p.zabel@pengutronix.de>,
	netdev <netdev@vger.kernel.org>,
	devicetree@vger.kernel.org, linux-arm-kernel@lists.infradead.org,
	"moderated list:ARM/Mediatek SoC support"
	<linux-mediatek@lists.infradead.org>,
	linux-kernel@vger.kernel.org,
	"René van Dorst" <opensource@vdorst.com>,
	"Frank Wunderlich" <frank-w@public-files.de>
Subject: Re: [PATCH net-next 2/2] drivers: net: dsa: mt7530: MT7530 optional GPIO support
Date: Mon, 11 Jan 2021 13:55:09 +0000	[thread overview]
Message-ID: <20210111135509.GT1551@shell.armlinux.org.uk> (raw)
In-Reply-To: <CALW65jaqciOiRxJxzPiEADgpmKa7-q2QfQnBdaVMcOa5YDHjRA@mail.gmail.com>

On Mon, Jan 11, 2021 at 09:40:00PM +0800, DENG Qingfang wrote:
> On Mon, Jan 11, 2021 at 7:04 PM Russell King - ARM Linux admin
> <linux@armlinux.org.uk> wrote:
> >
> > FYI, Documentation/driver-api/gpio/consumer.rst says:
> >
> >   For output GPIOs, the value provided becomes the initial output value.
> >   This helps avoid signal glitching during system startup.
> >
> > Setting the pin to be an output, and then setting its initial value
> > does not avoid the glitch. You may wish to investigate whether you
> > can set the value before setting the pin as an output to avoid this
> > issue.
> >
> 
> So, setting the Output Enable bit _after_ setting the direction and
> initial value should avoid this issue. Right?

It depends on the hardware. I don't know how your hardware works, so
I can't say whether doing anything will result in correct behaviour,
or even work.

-- 
RMK's Patch system: https://www.armlinux.org.uk/developer/patches/
FTTP is here! 40Mbps down 10Mbps up. Decent connectivity at last!

  reply	other threads:[~2021-01-11 13:56 UTC|newest]

Thread overview: 16+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-01-11  5:44 [PATCH net-next 0/2] dsa: add MT7530 GPIO support DENG Qingfang
2021-01-11  5:44 ` [PATCH net-next 1/2] dt-bindings: net: dsa: add MT7530 GPIO controller binding DENG Qingfang
2021-01-14 19:11   ` Rob Herring
2021-01-18 14:43   ` Linus Walleij
2021-01-11  5:44 ` [PATCH net-next 2/2] drivers: net: dsa: mt7530: MT7530 optional GPIO support DENG Qingfang
2021-01-11 11:04   ` Russell King - ARM Linux admin
2021-01-11 13:40     ` DENG Qingfang
2021-01-11 13:55       ` Russell King - ARM Linux admin [this message]
2021-01-18 14:55   ` Linus Walleij
2021-01-19  3:20     ` DENG Qingfang
2021-01-22 10:06       ` Linus Walleij
2021-01-11 13:43 ` [PATCH net-next 0/2] dsa: add MT7530 " Vladimir Oltean
2021-01-14  9:36   ` Bartosz Golaszewski
2021-01-11 15:46 ` Marek Behún
2021-01-12  2:50   ` DENG Qingfang
2021-01-14 17:08     ` Florian Fainelli

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=20210111135509.GT1551@shell.armlinux.org.uk \
    --to=linux@armlinux.org.uk \
    --cc=Landen.Chao@mediatek.com \
    --cc=andrew@lunn.ch \
    --cc=davem@davemloft.net \
    --cc=devicetree@vger.kernel.org \
    --cc=dqfext@gmail.com \
    --cc=f.fainelli@gmail.com \
    --cc=frank-w@public-files.de \
    --cc=kuba@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=olteanv@gmail.com \
    --cc=opensource@vdorst.com \
    --cc=p.zabel@pengutronix.de \
    --cc=robh+dt@kernel.org \
    --cc=sean.wang@mediatek.com \
    --cc=vivien.didelot@gmail.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;
as well as URLs for NNTP newsgroup(s).