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Date:   Mon, 9 Jul 2018 06:18:05 +0200
From:   Greg KH <greg@kroah.com>
To:     =?utf-8?B?0JDQu9C10LrRgdC10Lkg0JHRgNC+0LTQutC40L0=?= 
        <alexey.brodkin@gmail.com>
Cc:     linux-kernel@vger.kernel.org, linux-snps-arc@lists.infradead.org,
        linux-arch@vger.kernel.org, Alexey Brodkin <abrodkin@synopsys.com>,
        Thomas Gleixner <tglx@linutronix.de>, stable@vger.kernel.org
Subject: Re: [PATCH v2] devres: Really align data field to unsigned long long
Message-ID: <20180709041805.GA5983@kroah.com>
References: <20180708175621.6951-1-abrodkin@synopsys.com>
 <20180708184049.GA1645@kroah.com>
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On Sun, Jul 08, 2018 at 09:45:31PM +0300, Алексей Бродкин wrote:
> Hi Greg,
> 
> вс, 8 июл. 2018 г. в 21:40, Greg KH <greg@kroah.com>:
> >
> > On Sun, Jul 08, 2018 at 08:56:21PM +0300, Alexey Brodkin wrote:
> > > Depending on ABI "long long" type of a particular 32-bit CPU
> > > might be aligned by either word (32-bits) or double word (64-bits).
> > > Make sure "data" is really 64-bit aligned for any 32-bit CPU.
> > >
> > > At least for 32-bit ARC cores ABI requires "long long" types
> > > to be aligned by normal 32-bit word. This makes "data" field aligned to
> > > 12 bytes. Which is still OK as long as we use 32-bit data only.
> > >
> > > But once we want to use native atomic64_t type (i.e. when we use special
> > > instructions LLOCKD/SCONDD for accessing 64-bit data) we easily hit
> > > misaligned access exception.
> > >
> > > That's because even on CPUs capable of non-aligned data access LL/SC
> > > instructions require strict alignment.
> > >
> > > Signed-off-by: Alexey Brodkin <abrodkin@synopsys.com>
> > > Cc: Thomas Gleixner <tglx@linutronix.de>
> > > Cc: stable@vger.kernel.org
> > > ---
> > >
> > > Changes v1 -> v2:
> > >
> > >  * Reworded commit message
> > >  * Inserted comment right in source [Thomas]
> > >
> > >  drivers/base/devres.c | 8 ++++++--
> > >  1 file changed, 6 insertions(+), 2 deletions(-)
> >
> > Always use scripts/get_maintainer.pl to properly cc: the needed
> > developer/maintainer.  As it is, this patch is going to get dropped on
> > the floor, sorry...
> 
> Right I was way too relaxed dealing with very generic stuff which might get
> not that much of attention as more narrow topics or subsystems. But anyways
> get_maintainer.pl says you're the guy so do I need to do anything extra still or
> it's OK for this time?

Please resend it properly, it is not in my patch queue anywhere...

greg k-h