From: Andrew Lunn <andrew@lunn.ch>
To: Justin Chen <justin.chen@broadcom.com>
Cc: netdev@vger.kernel.org, Doug Berger <opendmb@gmail.com>,
Florian Fainelli <florian.fainelli@broadcom.com>,
Broadcom internal kernel review list
<bcm-kernel-feedback-list@broadcom.com>,
Heiner Kallweit <hkallweit1@gmail.com>,
Russell King <linux@armlinux.org.uk>,
"David S. Miller" <davem@davemloft.net>,
Eric Dumazet <edumazet@google.com>,
Jakub Kicinski <kuba@kernel.org>, Paolo Abeni <pabeni@redhat.com>,
open list <linux-kernel@vger.kernel.org>
Subject: Re: [PATCH] net: mdio: mdio-bcm-unimac: Delay before first poll
Date: Wed, 13 Dec 2023 11:57:52 +0100 [thread overview]
Message-ID: <c3cc7a9d-d464-48e7-beb7-b90b1abbcfc7@lunn.ch> (raw)
In-Reply-To: <20231213000249.2020835-1-justin.chen@broadcom.com>
On Tue, Dec 12, 2023 at 04:02:49PM -0800, Justin Chen wrote:
> With a clock interval of 400 nsec and a 64 bit transactions (32 bit
> preamble & 16 bit control & 16 bit data), it is reasonable to assume
> the mdio transaction will take 25.6 usec. Add a 30 usec delay before
> the first poll to reduce the chance of a 1000-2000 usec sleep.
#define MDIO_C45 0
suggests the hardware can do C45? The timing works out different then.
Maybe add a comment by the udelay() that is assumes C22, to give a
clue to somebody who is adding C45 support the delay needs to be
re-evaluated.
Andrew
next prev parent reply other threads:[~2023-12-13 10:58 UTC|newest]
Thread overview: 6+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-12-13 0:02 Justin Chen
2023-12-13 0:08 ` Florian Fainelli
2023-12-13 10:57 ` Andrew Lunn [this message]
2023-12-13 15:01 ` Russell King (Oracle)
2023-12-13 16:20 ` Florian Fainelli
2023-12-13 22:00 ` 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=c3cc7a9d-d464-48e7-beb7-b90b1abbcfc7@lunn.ch \
--to=andrew@lunn.ch \
--cc=bcm-kernel-feedback-list@broadcom.com \
--cc=davem@davemloft.net \
--cc=edumazet@google.com \
--cc=florian.fainelli@broadcom.com \
--cc=hkallweit1@gmail.com \
--cc=justin.chen@broadcom.com \
--cc=kuba@kernel.org \
--cc=linux-kernel@vger.kernel.org \
--cc=linux@armlinux.org.uk \
--cc=netdev@vger.kernel.org \
--cc=opendmb@gmail.com \
--cc=pabeni@redhat.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
all inboxes | Powered by JetHome®