From mboxrd@z Thu Jan  1 00:00:00 1970
From: shawnguo@kernel.org (Shawn Guo)
Date: Sat, 11 Jun 2016 19:57:33 +0800
Subject: [PATCH 1/1] ARM: dts: imx6qdl.dtsi: add "arm, shared-override"
 for pl310
In-Reply-To: <1465292365-26038-1-git-send-email-peter.chen@nxp.com>
References: <1465292365-26038-1-git-send-email-peter.chen@nxp.com>
Message-ID: <20160611115733.GM20243@tiger>
To: linux-arm-kernel@lists.infradead.org
List-Id: linux-arm-kernel.lists.infradead.org

+ Lucas

On Tue, Jun 07, 2016 at 05:39:25PM +0800, Peter Chen wrote:
> The imx6 SMP system has the same DMA memory coherency issue [1] with
> pl310 L2 controller. With this shared override bit set, the customer
> reports the DMA coherency issue is gone. Besides, I have tested
> the performance using USB ethernet with/without this bit, it shows
> no difference.
> 
> [1] http://patchwork.ozlabs.org/patch/469362/
> 
> Signed-off-by: Peter Chen <peter.chen@nxp.com>
> ---
>  arch/arm/boot/dts/imx6qdl.dtsi | 1 +
>  1 file changed, 1 insertion(+)
> 
> diff --git a/arch/arm/boot/dts/imx6qdl.dtsi b/arch/arm/boot/dts/imx6qdl.dtsi
> index ed613eb..30e21ee 100644
> --- a/arch/arm/boot/dts/imx6qdl.dtsi
> +++ b/arch/arm/boot/dts/imx6qdl.dtsi
> @@ -185,6 +185,7 @@
>  			cache-level = <2>;
>  			arm,tag-latency = <4 2 3>;
>  			arm,data-latency = <4 2 3>;
> +			arm,shared-override;

Lucas had an objection to the change [1], considering the case that
kernel is booted as non-secure.

Shawn

[1] http://thread.gmane.org/gmane.linux.ports.arm.kernel/471026

>  		};
>  
>  		pcie: pcie at 0x01000000 {
> -- 
> 1.9.1
> 
> 
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