netdev - Re: [PATCH] net: phy: Fix phy_modify() semantic difference fallout

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Message-ID: <20180109145010.GL17719@n2100.armlinux.org.uk>
Date:   Tue, 9 Jan 2018 14:50:10 +0000
From:   Russell King - ARM Linux <linux@...linux.org.uk>
To:     Andrew Lunn <andrew@...n.ch>
Cc:     Geert Uytterhoeven <geert+renesas@...der.be>,
        "David S . Miller" <davem@...emloft.net>,
        Florian Fainelli <f.fainelli@...il.com>,
        netdev@...r.kernel.org, linux-renesas-soc@...r.kernel.org,
        linux-kernel@...r.kernel.org
Subject: Re: [PATCH] net: phy: Fix phy_modify() semantic difference fallout

On Tue, Jan 09, 2018 at 03:48:13PM +0100, Andrew Lunn wrote:
> > > I took a quick look at the uses of phy_modify(). I don't see any uses
> > > of the return code other than as an error indicator. So having it
> > > return 0 on success seems like a better fix.
> > 
> > I'd like to avoid that, because I don't want to have yet another
> > accessor that needs to be used for advertisment modification (where
> > we need to know if we changed any bits.)
> > 
> > That's why this accessor returns the old value.
> 
> Hi Russell
> 
> where exactly is this use case? I've not found it yet.
> 
> I can understand your argument. But how long it is going to take us to
> find all the breakage because the return value has changed meaning?
> 
> The trade off is adding yet another accessor vs debugging and fixing
> the repercussions.
> 
> I think i prefer not breaking existing code.

Please introduce a new accessor then.

-- 
RMK's Patch system: http://www.armlinux.org.uk/developer/patches/
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