linux-kernel - Re: [PATCH 3/3] ARM: errata 430973: move !ARCH

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Date:	Sun, 26 Jul 2015 23:51:45 +0100
From:	Russell King - ARM Linux <linux@....linux.org.uk>
To:	Sebastian Reichel <sre@...nel.org>
Cc:	Tony Lindgren <tony@...mide.com>,
	linux-arm-kernel@...ts.infradead.org, linux-omap@...r.kernel.org,
	linux-kernel@...r.kernel.org
Subject: Re: [PATCH 3/3] ARM: errata 430973: move !ARCH_MULTIPLATFORM to
 Kconfig

On Fri, Jul 24, 2015 at 02:16:06AM +0200, Sebastian Reichel wrote:
> Hi Russel,
> 
> On Thu, Jul 23, 2015 at 01:35:53PM +0100, Russell King - ARM Linux wrote:
> > On Thu, Jul 23, 2015 at 02:48:03AM +0200, Sebastian Reichel wrote:
> > > Having the !ARCH_MULTIPLATFORM dependency in the Kconfig file results
> > > in one option less to think about when configuring the kernel.
> > 
> > > -#if defined(CONFIG_ARM_ERRATA_430973) && !defined(CONFIG_ARCH_MULTIPLATFORM)
> > > +#ifdef CONFIG_ARM_ERRATA_430973
> > >  	teq	r3, #0x00100000			@ only present in r1p*
> > >  	mrceq	p15, 0, r0, c1, c0, 1		@ read aux control register
> > >  	orreq	r0, r0, #(1 << 6)		@ set IBE to 1
> > 
> > NAK.  Please read the mailing list history, I'm not repeating myself
> > again on this.  Thanks.
> 
> It's a bit hard to search the mailing list history without a bit
> more information.

You were Cc'd on the previous round of review...

> I guess you prefer to just add the !ARCH_MULTIPLATFORM dependency to
> the Kconfig entry without removing the additional check in the code?

I was referring to the above change.

However, having discussed with Will Deacon and checked the manuals, I
think the change is okay after all: the auxillary control register is
banked on secure parts, and the bit we'll be trying to change will be
read-only in non-secure mode - and importantly won't fault.

So, the change is fine, thanks.

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