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Date: Fri, 19 Feb 2016 10:35:35 +0100
From: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
To: Marc Zyngier <marc.zyngier@arm.com>
Cc: Thomas Gleixner <tglx@linutronix.de>, Jason Cooper <jason@lakedaemon.net>,
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        Nadav Haklai <nadavh@marvell.com>, Lior Amsalem <alior@marvell.com>,
        linux-arm-kernel@lists.infradead.org
Subject: Re: [PATCH v2] irqchip: irq-mvebu-odmi: new driver for platform MSI
 on Marvell 7K/8K
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Marc,

On Thu, 18 Feb 2016 16:41:23 +0000, Marc Zyngier wrote:

> It looks really nice, except for a couple of points, see below.

Thanks again for the review.

> > +/*
> > + * We don't support the group events, so we simply have 8 interrupts
> > + * per frame.
> > + */
> > +#define NODMIS_PER_FRAME 8
> > +#define NODMIS_SHIFT     3
> > +#define NODMIS_MASK      7
> 
> All these values are directly related, so it would be nice if they would
> be expressed in term of each other:
> 
> #define NODMIS_SHIFT	 3
> #define NODMIS_PER_FRAME (1 << NODMIS_SHIFT)
> #define NODMIS_MASK      (NODMIS_PER_FRAME - 1)

Good point, will do.

> > +	odmis_bm = kzalloc(odmis_count * NODMIS_PER_FRAME / BITS_PER_BYTE,
> > +			   GFP_KERNEL);
> 
> Blah. this will allocate the exact number of bytes, which you will then
> access as longs, touching memory that's not yours in the process (I've
> been recently bitten and publicly shamed...).

Aah, yes.

> Consider the following:
> 
> odmis_bm = kzalloc(BITS_TO_LONGS(odmis_count * NODMIS_PER_FRAME) *
> sizeof(long), GFP_KERNEL);

Will do.

Thanks!

Thomas
-- 
Thomas Petazzoni, CTO, Free Electrons
Embedded Linux, Kernel and Android engineering
http://free-electrons.com