From: Andrew Lunn <andrew@lunn.ch>
To: Mike Looijmans <mike.looijmans@topic.nl>
Cc: netdev@vger.kernel.org, "David S. Miller" <davem@davemloft.net>,
Heiner Kallweit <hkallweit1@gmail.com>,
Jakub Kicinski <kuba@kernel.org>,
Russell King <linux@armlinux.org.uk>,
linux-kernel@vger.kernel.org
Subject: Re: [PATCH] net: mdiobus: Prevent spike on MDIO bus reset signal
Date: Thu, 28 Jan 2021 02:56:25 +0100 [thread overview]
Message-ID: <YBIZyWZNoQeJ7Bt4@lunn.ch> (raw)
In-Reply-To: <20210126073337.20393-1-mike.looijmans@topic.nl>
On Tue, Jan 26, 2021 at 08:33:37AM +0100, Mike Looijmans wrote:
> The mdio_bus reset code first de-asserted the reset by allocating with
> GPIOD_OUT_LOW, then asserted and de-asserted again. In other words, if
> the reset signal defaulted to asserted, there'd be a short "spike"
> before the reset.
>
> Instead, directly assert the reset signal using GPIOD_OUT_HIGH, this
> removes the spike and also removes a line of code since the signal
> is already high.
Hi Mike
Did you look at the per PHY reset? mdiobus_register_gpiod() gets the
GPIO with GPIOD_OUT_LOW. mdiobus_register_device() then immediately
sets it high.
So it looks like it suffers from the same problem.
Andrew
next prev parent reply other threads:[~2021-01-28 1:57 UTC|newest]
Thread overview: 13+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-01-26 7:33 [PATCH] net: mdiobus: Prevent spike on MDIO bus reset signal Mike Looijmans
2021-01-26 13:14 ` Andrew Lunn
2021-01-26 13:49 ` Russell King - ARM Linux admin
[not found] ` <1b153bce-a66a-45ee-a5c6-963ea6fb1c82.949ef384-8293-46b8-903f-40a477c056ae.b4d05392-d8bb-4828-9ac6-5a63736d3625@emailsignatures365.codetwo.com>
[not found] ` <1b153bce-a66a-45ee-a5c6-963ea6fb1c82.0d2bd5fa-15cc-4b27-b94e-83614f9e5b38.23e4b566-2e4d-4160-a40f-4bf79ef86f8a@emailsignatures365.codetwo.com>
2021-01-27 7:08 ` Mike Looijmans
2021-01-27 22:54 ` Jakub Kicinski
2021-01-28 0:00 ` Andrew Lunn
2021-01-28 0:25 ` Russell King - ARM Linux admin
2021-01-28 1:12 ` Andrew Lunn
[not found] ` <1b153bce-a66a-45ee-a5c6-963ea6fb1c82.949ef384-8293-46b8-903f-40a477c056ae.47109184-a5be-4b1d-bb22-724baf83e536@emailsignatures365.codetwo.com>
[not found] ` <1b153bce-a66a-45ee-a5c6-963ea6fb1c82.0d2bd5fa-15cc-4b27-b94e-83614f9e5b38.a2a17a1f-7cb0-46c3-bdd8-65266e08a153@emailsignatures365.codetwo.com>
2021-02-02 11:40 ` Mike Looijmans
2021-02-02 13:51 ` Andrew Lunn
2021-01-28 1:56 ` Andrew Lunn [this message]
[not found] ` <1b153bce-a66a-45ee-a5c6-963ea6fb1c82.949ef384-8293-46b8-903f-40a477c056ae.7228ddf2-6794-42a0-8b0b-3821446cdb40@emailsignatures365.codetwo.com>
[not found] ` <1b153bce-a66a-45ee-a5c6-963ea6fb1c82.0d2bd5fa-15cc-4b27-b94e-83614f9e5b38.7855d092-e2c3-4ba5-a029-2a0bbce637e1@emailsignatures365.codetwo.com>
2021-01-28 8:45 ` Mike Looijmans
2021-01-29 20:23 ` 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=YBIZyWZNoQeJ7Bt4@lunn.ch \
--to=andrew@lunn.ch \
--cc=davem@davemloft.net \
--cc=hkallweit1@gmail.com \
--cc=kuba@kernel.org \
--cc=linux-kernel@vger.kernel.org \
--cc=linux@armlinux.org.uk \
--cc=mike.looijmans@topic.nl \
--cc=netdev@vger.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.