From: Andrew Lunn <andrew@lunn.ch>
To: Andreas Schwab <schwab@suse.de>
Cc: alexandre.belloni@bootlin.com, f.fainelli@gmail.com,
Quentin Schulz <quentin.schulz@bootlin.com>,
netdev@vger.kernel.org, linux-kernel@vger.kernel.org,
allan.nielsen@microchip.com, thomas.petazzoni@bootlin.com,
linux-riscv@lists.infradead.org, davem@davemloft.net
Subject: Re: [PATCH net-next v3 1/6] net: phy: mscc: migrate to phy_select/restore_page functions
Date: Mon, 19 Nov 2018 16:28:30 +0100 [thread overview]
Message-ID: <20181119152830.GE26852@lunn.ch> (raw)
Message-ID: <20181119152830.G9QTZpQ4MaHa7tdYKJlYfshhJntra1bTt0TxmKuHYzw@z> (raw)
In-Reply-To: <mvm4lcdaynt.fsf@suse.de>
On Mon, Nov 19, 2018 at 04:13:10PM +0100, Andreas Schwab wrote:
> On Nov 19 2018, Andrew Lunn <andrew@lunn.ch> wrote:
>
> > On Mon, Nov 19, 2018 at 03:57:17PM +0100, Andreas Schwab wrote:
> >> On Okt 08 2018, Quentin Schulz <quentin.schulz@bootlin.com> wrote:
> >>
> >> > The Microsemi PHYs have multiple banks of registers (called pages).
> >> > Registers can only be accessed from one page, if we need a register from
> >> > another page, we need to switch the page and the registers of all other
> >> > pages are not accessible anymore.
> >> >
> >> > Basically, to read register 5 from page 0, 1, 2, etc., you do the same
> >> > phy_read(phydev, 5); but you need to set the desired page beforehand.
> >> >
> >> > In order to guarantee that two concurrent functions do not change the
> >> > page, we need to do some locking per page. This can be achieved with the
> >> > use of phy_select_page and phy_restore_page functions but phy_write/read
> >> > calls in-between those two functions shall be replaced by their
> >> > lock-free alternative __phy_write/read.
> >> >
> >> > Let's migrate this driver to those functions.
> >>
> >> This has some serious locking problem.
> >
> > Hi Andreas
> >
> > Could you be more specific. Are you getting a deadlock? A WARN_ON?
>
> See the stack trace. That's where it hangs.
So you never said it hangs. The stacktrace helps, but a description of
what actually happens also helps. And i expect Quentin has booted this
code lots of times and not had a hang. So some hits how to reproduce
it would also help. Maybe your kernel config?
I'm interested because he is using the core mdio locking
primitives. If those are broken, i want to know.
Thanks
Andrew
_______________________________________________
linux-riscv mailing list
linux-riscv@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-riscv
next prev parent reply other threads:[~2018-11-19 15:29 UTC|newest]
Thread overview: 34+ messages / expand[flat|nested] mbox.gz Atom feed top
[not found] <20181008100728.24959-1-quentin.schulz@bootlin.com>
[not found] ` <20181008100728.24959-2-quentin.schulz@bootlin.com>
2018-11-19 14:57 ` [PATCH net-next v3 1/6] net: phy: mscc: migrate to phy_select/restore_page functions Andreas Schwab
2018-11-19 14:57 ` Andreas Schwab
2018-11-19 15:10 ` Andrew Lunn
2018-11-19 15:10 ` Andrew Lunn
2018-11-19 15:13 ` Andreas Schwab
2018-11-19 15:13 ` Andreas Schwab
2018-11-19 15:28 ` Andrew Lunn [this message]
2018-11-19 15:28 ` Andrew Lunn
2018-11-19 15:40 ` Alexandre Belloni
2018-11-19 15:40 ` Alexandre Belloni
2018-11-19 15:50 ` Andreas Schwab
2018-11-19 15:50 ` Andreas Schwab
2018-11-19 16:12 ` Andrew Lunn
2018-11-19 16:12 ` Andrew Lunn
2018-11-19 16:14 ` Andreas Schwab
2018-11-19 16:14 ` Andreas Schwab
2018-11-19 16:25 ` Andrew Lunn
2018-11-19 16:25 ` Andrew Lunn
2018-11-19 16:32 ` Andreas Schwab
2018-11-19 16:32 ` Andreas Schwab
2018-11-19 16:44 ` Andrew Lunn
2018-11-19 16:44 ` Andrew Lunn
2018-11-20 11:39 ` Andreas Schwab
2018-11-20 11:39 ` Andreas Schwab
2018-11-20 13:20 ` Quentin Schulz
2018-11-20 13:20 ` Quentin Schulz
2018-11-20 13:48 ` [PATCH] net: phy: mscc: fix locking in vsc85xx_default_config Andreas Schwab
2018-11-20 13:48 ` Andreas Schwab
2018-11-20 13:55 ` Quentin Schulz
2018-11-20 13:55 ` Quentin Schulz
2018-11-20 14:01 ` Andreas Schwab
2018-11-20 14:01 ` Andreas Schwab
2018-11-20 14:17 ` Quentin Schulz
2018-11-20 14:17 ` Quentin Schulz
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=20181119152830.GE26852@lunn.ch \
--to=andrew@lunn.ch \
--cc=alexandre.belloni@bootlin.com \
--cc=allan.nielsen@microchip.com \
--cc=davem@davemloft.net \
--cc=f.fainelli@gmail.com \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-riscv@lists.infradead.org \
--cc=netdev@vger.kernel.org \
--cc=quentin.schulz@bootlin.com \
--cc=schwab@suse.de \
--cc=thomas.petazzoni@bootlin.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).