Re: [PATCH 5.10 079/122] net: phylink: add suspend/resume support

[Greg Kroah-Hartman]

On Tue, Sep 21, 2021 at 11:02:52PM +0100, Russell King (Oracle) wrote:
> 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?

Because they came in through two different sets of processes.  And
during the -rc1 merge window madness, we have lots to still catch up on
because of all of the "fixes" that people wait to get into the tree
then.

> 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.

Help is always gladly accepted.  Marking patches explicitly for stable
with a cc: stable is always the easiest way into the tree.  Otherwise we
have to do hueristics in looking at changelog text and Fixes: tags to
try to guess what is, and is not, valid for stable trees.

thanks,

greg k-h