[PATCH] arm64: dts: fast models: Increase clcd's max-memory-bandwidth

[PATCH] arm64: dts: fast models: Increase clcd's max-memory-bandwidth

[Kevin Brodsky]

It may be desirable on certain platforms, such as Android, to
use 32bpp buffers. Since there is no clear bandwidth limit for the
CLCD component on the fast model, let's increase
max-memory-bandwidth to allow using 32bpp buffers.

Reported-by: Ruben Ayrapetyan <ruben.ayrapetyan@arm.com>
Signed-off-by: Kevin Brodsky <kevin.brodsky@arm.com>
---
 arch/arm64/boot/dts/arm/fvp-base-revc.dts | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/arch/arm64/boot/dts/arm/fvp-base-revc.dts b/arch/arm64/boot/dts/arm/fvp-base-revc.dts
index 687707020ec1..3aee49ed6d88 100644
--- a/arch/arm64/boot/dts/arm/fvp-base-revc.dts
+++ b/arch/arm64/boot/dts/arm/fvp-base-revc.dts
@@ -269,7 +269,7 @@
 		motherboard {
 			iofpga@3,00000000 {
 				clcd@1f0000 {
-					max-memory-bandwidth = <130000000>; /* 16bpp @ 63.5MHz */
+					max-memory-bandwidth = <260000000>; /* 32bpp @ 63.5MHz */
 				};
 			};
 		};
-- 
2.22.0


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Re: [PATCH] arm64: dts: fast models: Increase clcd's max-memory-bandwidth

[Robin Murphy]

Hi Kevin,

On 25/07/2019 15:50, Kevin Brodsky wrote:
> It may be desirable on certain platforms, such as Android, to
> use 32bpp buffers. Since there is no clear bandwidth limit for the
> CLCD component on the fast model, let's increase
> max-memory-bandwidth to allow using 32bpp buffers.

Given that the property is optional anyway, would it hurt to just remove 
it? After trying to dig up any relevant internal email history, it's 
still far from clear how and why it got here in the first place.

Robin.

> Reported-by: Ruben Ayrapetyan <ruben.ayrapetyan@arm.com>
> Signed-off-by: Kevin Brodsky <kevin.brodsky@arm.com>
> ---
>   arch/arm64/boot/dts/arm/fvp-base-revc.dts | 2 +-
>   1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/arch/arm64/boot/dts/arm/fvp-base-revc.dts b/arch/arm64/boot/dts/arm/fvp-base-revc.dts
> index 687707020ec1..3aee49ed6d88 100644
> --- a/arch/arm64/boot/dts/arm/fvp-base-revc.dts
> +++ b/arch/arm64/boot/dts/arm/fvp-base-revc.dts
> @@ -269,7 +269,7 @@
>   		motherboard {
>   			iofpga@3,00000000 {
>   				clcd@1f0000 {
> -					max-memory-bandwidth = <130000000>; /* 16bpp @ 63.5MHz */
> +					max-memory-bandwidth = <260000000>; /* 32bpp @ 63.5MHz */
>   				};
>   			};
>   		};
> 

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Re: [PATCH] arm64: dts: fast models: Increase clcd's max-memory-bandwidth

[Kevin Brodsky]

On 25/07/2019 16:15, Robin Murphy wrote:
> Hi Kevin,

Hi Robin,

> On 25/07/2019 15:50, Kevin Brodsky wrote:
>> It may be desirable on certain platforms, such as Android, to
>> use 32bpp buffers. Since there is no clear bandwidth limit for the
>> CLCD component on the fast model, let's increase
>> max-memory-bandwidth to allow using 32bpp buffers.
> Given that the property is optional anyway, would it hurt to just remove
> it? After trying to dig up any relevant internal email history, it's
> still far from clear how and why it got here in the first place.

Very good point, I hadn't realised it was an optional property. Removing it 
completely seems to work fine. I'll send a v2 removing it from both fvp-base-revc.dts 
and rtsm_ve-motherboard.dtsi. Thanks!

Kevin

> Robin.
>
>> Reported-by: Ruben Ayrapetyan <ruben.ayrapetyan@arm.com>
>> Signed-off-by: Kevin Brodsky <kevin.brodsky@arm.com>
>> ---
>>    arch/arm64/boot/dts/arm/fvp-base-revc.dts | 2 +-
>>    1 file changed, 1 insertion(+), 1 deletion(-)
>>
>> diff --git a/arch/arm64/boot/dts/arm/fvp-base-revc.dts b/arch/arm64/boot/dts/arm/fvp-base-revc.dts
>> index 687707020ec1..3aee49ed6d88 100644
>> --- a/arch/arm64/boot/dts/arm/fvp-base-revc.dts
>> +++ b/arch/arm64/boot/dts/arm/fvp-base-revc.dts
>> @@ -269,7 +269,7 @@
>>    		motherboard {
>>    			iofpga@3,00000000 {
>>    				clcd@1f0000 {
>> -					max-memory-bandwidth = <130000000>; /* 16bpp @ 63.5MHz */
>> +					max-memory-bandwidth = <260000000>; /* 32bpp @ 63.5MHz */
>>    				};
>>    			};
>>    		};
>>


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Re: [PATCH] arm64: dts: fast models: Increase clcd's max-memory-bandwidth

[Linus Walleij]

On Thu, Jul 25, 2019 at 5:15 PM Robin Murphy <robin.murphy@arm.com> wrote:

> Given that the property is optional anyway, would it hurt to just remove
> it? After trying to dig up any relevant internal email history, it's
> still far from clear how and why it got here in the first place.

Isn't it just my sloppy copy-paste when fixing up the device trees
for the DRM transition? I agree it should just be removed.

Yours,
Linus Walleij

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