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From: Russell King - ARM Linux <linux@arm.linux.org.uk>
To: linux-arm-kernel@lists.infradead.org
Subject: Re: [PATCH 2/2] arm: Add ARM ERRATA 782773 workaround
Date: Thu, 13 Sep 2012 17:20:57 +0000	[thread overview]
Message-ID: <20120913172057.GB13739@n2100.arm.linux.org.uk> (raw)
In-Reply-To: <20120913010041.GD7622@verge.net.au>

On Thu, Sep 13, 2012 at 10:00:42AM +0900, Simon Horman wrote:
> +config ARM_ERRATA_782773
> +	bool "ARM errata: Updating a translation entry might cause an unexpected translation fault"
> +	depends on CPU_V7
> +	help
> +	  This option enables the workaround for the 782773 Cortex-A9 (all r0,
> +	  r2 and r3 revisions) erratum. It might cause MMU exception in case
> +	  page table walk happens just after updating the existing
> +	  with setting page table in L1 data cache.

What if we're running on a SMP system where the L1 caches are mandated
to be in write-allocate mode?  This write will immediately cause the
cache line to be brought back into the cache.

This sounds like a broken work-around to me.

  reply	other threads:[~2012-09-13 17:20 UTC|newest]

Thread overview: 15+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2012-09-12  7:14 [PATCH 0/2] ARM ERRATA 775420 and 782773 workarounds Simon Horman
2012-09-12  7:14 ` [PATCH 1/2] arm: Add ARM ERRATA 775420 workaround Simon Horman
2012-09-20  9:58   ` Catalin Marinas
2012-09-21  1:04     ` Simon Horman
2012-09-21  8:29       ` Catalin Marinas
2012-09-12  7:14 ` [PATCH 2/2] arm: Add ARM ERRATA 782773 workaround Simon Horman
2012-09-12 17:59   ` Stephen Boyd
2012-09-13  1:00     ` Simon Horman
2012-09-13 17:20       ` Russell King - ARM Linux [this message]
2012-09-20  9:32         ` Catalin Marinas
2012-09-20  9:35       ` Catalin Marinas
2012-09-21  1:00         ` Simon Horman
2012-09-28  1:02           ` Simon Horman
2012-09-28  8:38             ` Catalin Marinas
2012-10-03  2:19               ` Simon Horman

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