Re: [PATCH 5.10 012/105] dmaengine: shdma: Fix runtime PM imbalance on error

From: Pavel Machek
Date: Wed Mar 09 2022 - 07:35:17 EST


On Wed 2022-03-09 12:58:46, Greg Kroah-Hartman wrote:
> On Wed, Mar 09, 2022 at 11:54:20AM +0100, Pavel Machek wrote:
> > Hi!
> >
> > > From: Yongzhi Liu <lyz_cs@xxxxxxxxxx>
> > >
> > > [ Upstream commit 455896c53d5b803733ddd84e1bf8a430644439b6 ]
> > >
> > > pm_runtime_get_() increments the runtime PM usage counter even
> > > when it returns an error code, thus a matching decrement is needed on
> > > the error handling path to keep the counter balanced.
> >
> > This patch will break things.
> >
> > Notice that -ret is ignored (checked 4.4 and 5.10), so we don't
> > actually abort/return error; we just printk. We'll do two
> > pm_runtime_put's after the "fix".
> >
> > Please drop from -stable.
> >
> > It was discussed during AUTOSEL review:
> >
> > Date: Fri, 25 Feb 2022 14:25:10 +0800 (GMT+08:00)
> > From: 刘永志 <lyz_cs@xxxxxxxxxx>
> > To: pavel machek <pavel@xxxxxxx>
> > Cc: sasha levin <sashal@xxxxxxxxxx>, linux-kernel@xxxxxxxxxxxxxxx,
> > Subject: Re: [PATCH AUTOSEL 5.16 24/30] dmaengine: shdma: Fix runtime PM
> > imbalance on error
>
> So 5.15 and 5.16 is ok, but older is not?

I believe commit is wrong for mainline and all stable releases, and
author seems to agree. Drop from everywhere.

(And sorry for confusion, I concentrate on 5.10/4.19; that's why mail
was ambiguous).

Best regards,
Pavel
--
DENX Software Engineering GmbH, Managing Director: Wolfgang Denk
HRB 165235 Munich, Office: Kirchenstr.5, D-82194 Groebenzell, Germany

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