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ARM: Assume maintainership of ARM reference designs

Message ID 20180412140201.GI16141@n2100.armlinux.org.uk (mailing list archive)
State New, archived
Headers show

Commit Message

Russell King (Oracle) April 12, 2018, 2:02 p.m. UTC 
On Thu, Apr 12, 2018 at 03:59:20PM +0200, Linus Walleij wrote:
> On Thu, Apr 12, 2018 at 3:52 PM, Russell King - ARM Linux
> <linux@armlinux.org.uk> wrote:
> >  The Versatile Express
> > CT9x4 is still part of the boot farm, and just about works with
> > certain kernels, but I'm pretty sure there's a cache latency bug
> > there (I carry patches privately to fix it, but it doesn't appear to
> > completely solve it.)
> 
> So there is a bug in it! I thought it was only my board.

I'm not sure if it's a hardware bug or not...  This patch seems to
help immensely, but doesn't completely solve the problem:

Comments

Sudeep Holla April 12, 2018, 2:19 p.m. UTC | #1 
On 12/04/18 15:02, Russell King - ARM Linux wrote:
> On Thu, Apr 12, 2018 at 03:59:20PM +0200, Linus Walleij wrote:
>> On Thu, Apr 12, 2018 at 3:52 PM, Russell King - ARM Linux
>> <linux@armlinux.org.uk> wrote:
>>>  The Versatile Express
>>> CT9x4 is still part of the boot farm, and just about works with
>>> certain kernels, but I'm pretty sure there's a cache latency bug
>>> there (I carry patches privately to fix it, but it doesn't appear to
>>> completely solve it.)
>>
>> So there is a bug in it! I thought it was only my board.
> 
> I'm not sure if it's a hardware bug or not...  This patch seems to
> help immensely, but doesn't completely solve the problem:
> 

Every time I tried to debug this connecting the debugger, the execution
just automatically continues. Hence I tried playing around with these
latencies, but as you mentioned it just helps but doesn't solved the
problem.

> diff --git a/arch/arm/boot/dts/vexpress-v2p-ca9.dts b/arch/arm/boot/dts/vexpress-v2p-ca9.dts
> index 5814460e0549..56308c1c0208 100644
> --- a/arch/arm/boot/dts/vexpress-v2p-ca9.dts
> +++ b/arch/arm/boot/dts/vexpress-v2p-ca9.dts
> @@ -174,7 +174,7 @@
>  		cache-unified;
>  		cache-level = <2>;
>  		arm,data-latency = <1 1 1>;
> -		arm,tag-latency = <1 1 1>;
> +		arm,tag-latency = <2 2 1>;
>  	};
>  
>  	pmu {
>
diff mbox

Patch

diff --git a/arch/arm/boot/dts/vexpress-v2p-ca9.dts b/arch/arm/boot/dts/vexpress-v2p-ca9.dts
index 5814460e0549..56308c1c0208 100644
--- a/arch/arm/boot/dts/vexpress-v2p-ca9.dts
+++ b/arch/arm/boot/dts/vexpress-v2p-ca9.dts
@@ -174,7 +174,7 @@ 
 		cache-unified;
 		cache-level = <2>;
 		arm,data-latency = <1 1 1>;
-		arm,tag-latency = <1 1 1>;
+		arm,tag-latency = <2 2 1>;
 	};
 
 	pmu {