From: Andrew Lunn <andrew@lunn.ch>
To: Claudiu.Beznea@microchip.com
Cc: harini.katakam@xilinx.com, Nicolas.Ferre@microchip.com,
davem@davemloft.net, netdev@vger.kernel.org,
linux-kernel@vger.kernel.org, michal.simek@xilinx.com,
harinikatakamlinux@gmail.com, harinik@xilinx.com,
shubhrajyoti.datta@xilinx.com, sai.pavan.boddu@xilinx.com
Subject: Re: [PATCH v2 1/4] net: macb: Check MDIO state before read/write and use timeouts
Date: Mon, 26 Nov 2018 15:52:10 +0100 [thread overview]
Message-ID: <20181126145210.GD12116@lunn.ch> (raw)
In-Reply-To: <5de882e3-65ac-7ff1-bb55-7537666dfc77@microchip.com>
On Mon, Nov 26, 2018 at 02:46:01PM +0000, Claudiu.Beznea@microchip.com wrote:
> Hi Harini,
>
> On 26.11.2018 09:07, Harini Katakam wrote:
> > From: Harini Katakam <harinik@xilinx.com>
> >
> > Replace the while loop in MDIO read/write functions with a timeout.
> > In addition, add a check for MDIO bus busy before initiating a new
> > operation as well to make sure there is no ongoing MDIO operation.
>
> Is this MDIO bus busy check necessary? The caller of
> macb_mdio_read/macb_mdio_write locks the mdio bus mutex before calling it
> (e.g. mdiobus_read).
Hi Claudiu
It depends on the implementation. A write operation you could just
launch, but not wait for it to complete, allowing you to do other
stuff while the hardware is busy. For the next operation you then do
need to check the previous operation has completed.
I've not checked it is actually implemented this way.
Andrew
next prev parent reply other threads:[~2018-11-26 14:52 UTC|newest]
Thread overview: 19+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-11-26 7:07 [PATCH v2 0/4] Macb power management support for ZynqMP Harini Katakam
2018-11-26 7:07 ` [PATCH v2 1/4] net: macb: Check MDIO state before read/write and use timeouts Harini Katakam
2018-11-26 14:39 ` Andrew Lunn
2018-11-27 5:38 ` Harini Katakam
2018-11-26 14:46 ` Claudiu.Beznea
2018-11-26 14:52 ` Andrew Lunn [this message]
2018-11-27 5:36 ` Harini Katakam
2018-11-27 10:25 ` Claudiu.Beznea
2018-11-27 10:49 ` Harini Katakam
2018-11-28 0:35 ` Andrew Lunn
2018-11-29 10:21 ` Claudiu.Beznea
2018-11-26 7:07 ` [PATCH v2 2/4] net: macb: Support clock management for tsu_clk Harini Katakam
2018-11-26 7:07 ` [PATCH v2 3/4] net: macb: Add pm runtime support Harini Katakam
2018-11-26 14:47 ` Andrew Lunn
2018-11-26 14:47 ` Claudiu.Beznea
2018-11-26 7:07 ` [PATCH v2 4/4] net: macb: Add support for suspend/resume with full power down Harini Katakam
2018-11-26 14:46 ` Claudiu.Beznea
2018-11-27 6:25 ` Harini Katakam
2018-11-27 10:31 ` Claudiu.Beznea
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=20181126145210.GD12116@lunn.ch \
--to=andrew@lunn.ch \
--cc=Claudiu.Beznea@microchip.com \
--cc=Nicolas.Ferre@microchip.com \
--cc=davem@davemloft.net \
--cc=harini.katakam@xilinx.com \
--cc=harinik@xilinx.com \
--cc=harinikatakamlinux@gmail.com \
--cc=linux-kernel@vger.kernel.org \
--cc=michal.simek@xilinx.com \
--cc=netdev@vger.kernel.org \
--cc=sai.pavan.boddu@xilinx.com \
--cc=shubhrajyoti.datta@xilinx.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).