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Date:   Tue, 21 Sep 2021 23:02:52 +0100
From:   "Russell King (Oracle)" <linux@armlinux.org.uk>
To:     Pavel Machek <pavel@denx.de>
Cc:     Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
        linux-kernel@vger.kernel.org, stable@vger.kernel.org,
        Joakim Zhang <qiangqing.zhang@nxp.com>,
        "David S. Miller" <davem@davemloft.net>,
        Sasha Levin <sashal@kernel.org>
Subject: Re: [PATCH 5.10 079/122] net: phylink: add suspend/resume support
Message-ID: <YUpWjKZyqHImRaix@shell.armlinux.org.uk>
References: <20210920163915.757887582@linuxfoundation.org>
 <20210920163918.373775935@linuxfoundation.org>
 <20210921212837.GA29170@duo.ucw.cz>
 <YUpPmRPczcLveKj4@shell.armlinux.org.uk>
 <20210921214528.GA30221@duo.ucw.cz>
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Sender: Russell King (Oracle) <linux@armlinux.org.uk>
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On Tue, Sep 21, 2021 at 11:45:28PM +0200, Pavel Machek wrote:
> Hi!
> 
> > > > Joakim Zhang reports that Wake-on-Lan with the stmmac ethernet driver broke
> > > > when moving the incorrect handling of mac link state out of mac_config().
> > > > This reason this breaks is because the stmmac's WoL is handled by the MAC
> > > > rather than the PHY, and phylink doesn't cater for that scenario.
> > > > 
> > > > This patch adds the necessary phylink code to handle suspend/resume events
> > > > according to whether the MAC still needs a valid link or not. This is the
> > > > barest minimum for this support.
> > > 
> > > This adds functions that end up being unused in 5.10. AFAICT we do not
> > > need this in 5.10.
> > 
> > It needs to be backported to any kernel that also has
> > "net: stmmac: fix MAC not working when system resume back with WoL active"
> > backported to. From what I can tell, the fixes line in that commit
> > refers to a commit (46f69ded988d) in v5.7-rc1.
> > 
> > If "net: stmmac: fix MAC not working when system resume back with WoL
> > active" is not being backported to 5.10, then there is no need to
> > backport this patch.
> 
> Agreed.
> 
> > As I'm not being copied on the stmmac commit, I've no idea which kernels
> > this patch should be backported to.
> 
> AFAICT "net: stmmac: fix MAC not working when..." is not queued for
> 5.10.68-rc1 or 5.14.7-rc1.

Okay, this is madness. What is going on with stable's patch selection?
The logic seems completely reversed.

"net: phylink: Update SFP selected interface on advertising changes"
does not have a Fixes tag, and is not a fix in itself, yet has been
picked up by the stable team. It lays the necessary work for its
counter-part patch, which is...

"net: stmmac: fix system hang caused by eee_ctrl_timer during
suspend/resume" _has_ a Fixes tag, but has *not* been picked up by
the stable team.

It seems there's something very wrong process-wise here. Why would
a patch _without_ a Fixes line and isn't a fix in itself be picked
out for stable backport when patches with a Fixes line are ignored?

Not unless the stable plan is to apply "net: phylink: Update SFP
selected interface on advertising changes" and then sometime later
apply "net: stmmac: fix system hang caused by eee_ctrl_timer during
suspend/resume". No idea.

It all seems very weird and the process seems broken to me.

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