Re: [PATCH] ArmPkg/ArmGicDxe ARM: fix encoding for GICv3 interrupt acknowledge

[Leif Lindholm <leif.lindholm@linaro.org>]

On Wed, Nov 14, 2018 at 11:27:24AM -0800, Ard Biesheuvel wrote:
> Fix a typo in the 32-bit ARM version of the GICv3 driver, which uses
> the wrong system register encoding to access ICC_IAR1, and attempted
> to access ICC_IAR0 instead. This results in boot time hangs both
> under QEMU emulation and on real hardware.
> 
> Contributed-under: TianoCore Contribution Agreement 1.1
> Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>

Reviewed-by: Leif Lindholm <leif.lindholm@linaro.org>

I would say given how long we've gone without finding this, it's not
justifiable to push this before the stable tag is made - so please
hold off on pushing it until we open the flood gates.

/
    Leif

> ---
>  ArmPkg/Drivers/ArmGic/GicV3/Arm/ArmGicV3.S   | 2 +-
>  ArmPkg/Drivers/ArmGic/GicV3/Arm/ArmGicV3.asm | 2 +-
>  2 files changed, 2 insertions(+), 2 deletions(-)
> 
> diff --git a/ArmPkg/Drivers/ArmGic/GicV3/Arm/ArmGicV3.S b/ArmPkg/Drivers/ArmGic/GicV3/Arm/ArmGicV3.S
> index a72f3c865163..c308d2fa3e2f 100644
> --- a/ArmPkg/Drivers/ArmGic/GicV3/Arm/ArmGicV3.S
> +++ b/ArmPkg/Drivers/ArmGic/GicV3/Arm/ArmGicV3.S
> @@ -66,7 +66,7 @@ ASM_FUNC(ArmGicV3EndOfInterrupt)
>  //  VOID
>  //  );
>  ASM_FUNC(ArmGicV3AcknowledgeInterrupt)
> -        mrc     p15, 0, r0, c12, c8, 0 //ICC_IAR1
> +        mrc     p15, 0, r0, c12, c12, 0 //ICC_IAR1
>          bx      lr
>  
>  //VOID
> diff --git a/ArmPkg/Drivers/ArmGic/GicV3/Arm/ArmGicV3.asm b/ArmPkg/Drivers/ArmGic/GicV3/Arm/ArmGicV3.asm
> index 4228fb59be54..222047d1ad43 100644
> --- a/ArmPkg/Drivers/ArmGic/GicV3/Arm/ArmGicV3.asm
> +++ b/ArmPkg/Drivers/ArmGic/GicV3/Arm/ArmGicV3.asm
> @@ -66,7 +66,7 @@
>  //  VOID
>  //  );
>   RVCT_ASM_EXPORT ArmGicV3AcknowledgeInterrupt
> -        mrc     p15, 0, r0, c12, c8, 0 //ICC_IAR1
> +        mrc     p15, 0, r0, c12, c12, 0 //ICC_IAR1
>          bx      lr
>  
>  //VOID
> -- 
> 2.17.1
>