linux-kernel - RE: [PATCH] i2c: xiic: Fix reference count leaks.

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Date:   Wed, 17 Jun 2020 14:30:31 +0000
From:   David Laight <David.Laight@...LAB.COM>
To:     'Wolfram Sang' <wsa@...nel.org>,
        "wu000273@....edu" <wu000273@....edu>
CC:     "kjlu@....edu" <kjlu@....edu>,
        Michal Simek <michal.simek@...inx.com>,
        Rob Herring <robh@...nel.org>,
        Shubhrajyoti Datta <shubhraj@...inx.com>,
        "linux-arm-kernel@...ts.infradead.org" 
        <linux-arm-kernel@...ts.infradead.org>,
        "linux-i2c@...r.kernel.org" <linux-i2c@...r.kernel.org>,
        "linux-kernel@...r.kernel.org" <linux-kernel@...r.kernel.org>
Subject: RE: [PATCH] i2c: xiic: Fix reference count leaks.

From: Wolfram Sang
> Sent: 14 June 2020 10:10
> 
> On Sat, Jun 13, 2020 at 04:59:23PM -0500, wu000273@....edu wrote:
> > From: Qiushi Wu <wu000273@....edu>
> >
> > pm_runtime_get_sync() increments the runtime PM usage counter even
> > when it returns an error code. Thus call pm_runtime_put_noidle()
> > if pm_runtime_get_sync() fails.
> 
> Can you point me to a discussion where it was decided that this is a
> proper fix? I'd think we rather should fix pm_runtime_get_sync() but
> maybe there are technical reasons against it.

Or, if there is one place that actually needs the reference split the
code so that unusual case keeps the reference.

In one of the patches I also spotted:
	ret = pm_runtime_get_sync();
	if (ret < 0 && ret != _EAGAIN)
		...

(I think it was EAGAIN.)
I can't help feeling that is just wrong somewhere.

	David

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