From: andrew@lunn.ch (Andrew Lunn)
To: linux-riscv@lists.infradead.org
Subject: [PATCH net-next v3 1/6] net: phy: mscc: migrate to phy_select/restore_page functions
Date: Mon, 19 Nov 2018 16:10:57 +0100 [thread overview]
Message-ID: <20181119151057.GC26852@lunn.ch> (raw)
In-Reply-To: <mvm8t1pazea.fsf@suse.de>
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?
Thanks,
Andrew
WARNING: multiple messages have this Message-ID (diff)
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 16:10:57 +0100 [thread overview]
Message-ID: <20181119151057.GC26852@lunn.ch> (raw)
Message-ID: <20181119151057.TZ3ALoW3a1XbSyPi2VRXwKdKADEXhFe4zCCgFMiYzFs@z> (raw)
In-Reply-To: <mvm8t1pazea.fsf@suse.de>
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?
Thanks,
Andrew
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next prev parent reply other threads:[~2018-11-19 15:10 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 [this message]
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
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
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