From: Niklas Cassel <niklas.cassel@axis•com>
To: Andrew Lunn <andrew@lunn•ch>
Cc: David Miller <davem@davemloft•net>,
geert@linux-m68k•org, Russell King <rmk+kernel@arm•linux.org.uk>,
Florian Fainelli <f.fainelli@gmail•com>,
netdev <netdev@vger•kernel.org>
Subject: Re: [PATCH v2] net: phy: Have __phy_modify return 0 on success
Date: Mon, 15 Jan 2018 10:06:41 +0100 [thread overview]
Message-ID: <20180115090641.GA7399@axis.com> (raw)
In-Reply-To: <1515765696-1286-1-git-send-email-andrew@lunn.ch>
Tested-by: Niklas Cassel <niklas.cassel@axis•com>
On Fri, Jan 12, 2018 at 03:01:36PM +0100, Andrew Lunn wrote:
> __phy_modify would return the old value of the register before it was
> modified. Thus on success, it does not return 0, but a positive value.
> Thus functions using phy_modify, which is a wrapper around
> __phy_modify, can start returning > 0 on success, rather than 0. As a
> result, breakage has been noticed in various places, where 0 was
> assumed.
>
> Code inspection does not find any current location where the return of
> the old value is currently used. So have __phy_modify return 0 on
> success. When there is a real need for the old value, either a new
> accessor can be added, or an additional parameter passed.
>
> Fixes: fea23fb591cc ("net: phy: convert read-modify-write to phy_modify()")
> Fixes: 2b74e5be17d2 ("net: phy: add phy_modify() accessor")
> Reported-by: Geert Uytterhoeven <geert@linux-m68k•org>
> Tested-by: Geert Uytterhoeven <geert+renesas@glider•be>
> Signed-off-by: Andrew Lunn <andrew@lunn•ch>
> ---
> v2: space before :
> additional fixes tag
> Tested-by
> ---
> drivers/net/phy/phy-core.c | 13 ++++++-------
> 1 file changed, 6 insertions(+), 7 deletions(-)
>
> diff --git a/drivers/net/phy/phy-core.c b/drivers/net/phy/phy-core.c
> index e75989ce8850..4083f00c97a5 100644
> --- a/drivers/net/phy/phy-core.c
> +++ b/drivers/net/phy/phy-core.c
> @@ -336,16 +336,15 @@ EXPORT_SYMBOL(phy_write_mmd);
> */
> int __phy_modify(struct phy_device *phydev, u32 regnum, u16 mask, u16 set)
> {
> - int ret, res;
> + int ret;
>
> ret = __phy_read(phydev, regnum);
> - if (ret >= 0) {
> - res = __phy_write(phydev, regnum, (ret & ~mask) | set);
> - if (res < 0)
> - ret = res;
> - }
> + if (ret < 0)
> + return ret;
>
> - return ret;
> + ret = __phy_write(phydev, regnum, (ret & ~mask) | set);
> +
> + return ret < 0 ? ret : 0;
> }
> EXPORT_SYMBOL_GPL(__phy_modify);
>
> --
> 2.15.1
>
next prev parent reply other threads:[~2018-01-15 9:06 UTC|newest]
Thread overview: 5+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-01-12 14:01 [PATCH v2] net: phy: Have __phy_modify return 0 on success Andrew Lunn
2018-01-14 18:04 ` Andrew Lunn
2018-01-14 18:29 ` David Miller
2018-01-15 9:06 ` Niklas Cassel [this message]
2018-01-15 17:50 ` David Miller
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