[U-Boot] [PATCH v3 2/3] ARM: Add workaround for Cortex-A9 errata 761320

[Stefano Babic <sbabic@denx.de>]

Hi Nitin,

On 02/04/2014 15:55, nitin.garg at freescale.com wrote:
> From: Nitin Garg <nitin.garg@freescale.com>
> 
> Full cache line writes to the same memory region from at least two
> processors might deadlock the processor. Exists on r1, r2, r3
> revisions.
> 
> Signed-off-by: Nitin Garg <nitin.garg@freescale.com>
> ---
>  README                     |    1 +
>  arch/arm/cpu/armv7/start.S |    5 +++++
>  2 files changed, 6 insertions(+), 0 deletions(-)
> 
> diff --git a/README b/README
> index a496c65..b7c0f68 100644
> --- a/README
> +++ b/README
> @@ -567,6 +567,7 @@ The following options need to be configured:
>  		CONFIG_ARM_ERRATA_743622
>  		CONFIG_ARM_ERRATA_751472
>  		CONFIG_ARM_ERRATA_794072
> +		CONFIG_ARM_ERRATA_761320
>  
>  		If set, the workarounds for these ARM errata are applied early
>  		during U-Boot startup. Note that these options force the
> diff --git a/arch/arm/cpu/armv7/start.S b/arch/arm/cpu/armv7/start.S
> index f3830c8..27be451 100644
> --- a/arch/arm/cpu/armv7/start.S
> +++ b/arch/arm/cpu/armv7/start.S
> @@ -222,6 +222,11 @@ ENTRY(cpu_init_cp15)
>  	orr	r0, r0, #1 << 11	@ set bit #11
>  	mcr	p15, 0, r0, c15, c0, 1	@ write diagnostic register
>  #endif
> +#ifdef CONFIG_ARM_ERRATA_761320
> +	mrc	p15, 0, r0, c15, c0, 1	@ read diagnostic register
> +	orr	r0, r0, #1 << 21	@ set bit #21
> +	mcr	p15, 0, r0, c15, c0, 1	@ write diagnostic register
> +#endif
>  
>  	mov	pc, lr			@ back to my caller
>  ENDPROC(cpu_init_cp15)
> 

I admit I am not able to find the documentation for this errata neither
the ARM center nor in the i.MX6 errata. Do you have a link to get some
more infos about it ?

Best regards,
Stefano Babic

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