arm64: dts: mediatek: mt8188-geralt: Enlarge SCP core0 memory region

[PATCH] arm64: dts: mediatek: mt8188-geralt: Enlarge SCP core0 memory region

Posted by Justin Yeh 1 month ago

The SCP firmware in linux-firmware for this platform
(mediatek/mt8188/scp_c0.img) supports MDP, which the mdp3-rdma node
drives through scp_c0. On top of the segments it loads, the firmware
allocates a 1 MiB DMA region at 0x50800000 at run time. That lies
outside the 8 MiB reserved for SCP core0, so Linux is free to allocate
over memory the firmware uses.

Enlarge the region to 9 MiB. apu_mem starts at 0x55000000, so no other
reserved region has to move.

Fixes: e36be19823f0 ("arm64: dts: mediatek: mt8188-geralt: Enable first SCP core")
Signed-off-by: Justin Yeh <justin.yeh@mediatek.com>
---
 arch/arm64/boot/dts/mediatek/mt8188-geralt.dtsi | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/arch/arm64/boot/dts/mediatek/mt8188-geralt.dtsi b/arch/arm64/boot/dts/mediatek/mt8188-geralt.dtsi
index f382f90c48f5..35f60b5bba6f 100644
--- a/arch/arm64/boot/dts/mediatek/mt8188-geralt.dtsi
+++ b/arch/arm64/boot/dts/mediatek/mt8188-geralt.dtsi
@@ -166,7 +166,7 @@ reserved_memory: reserved-memory {
 
 		scp_mem_reserved: memory@50000000 {
 			compatible = "shared-dma-pool";
-			reg = <0 0x50000000 0 0x800000>;
+			reg = <0 0x50000000 0 0x900000>;
 			no-map;
 		};
 
-- 
2.45.2

Re: [PATCH] arm64: dts: mediatek: mt8188-geralt: Enlarge SCP core0 memory region

Posted by AngeloGioacchino Del Regno 2 weeks, 4 days ago

On Mon, 24 Aug 2026 17:04:00 +0800, Justin Yeh wrote:
> The SCP firmware in linux-firmware for this platform
> (mediatek/mt8188/scp_c0.img) supports MDP, which the mdp3-rdma node
> drives through scp_c0. On top of the segments it loads, the firmware
> allocates a 1 MiB DMA region at 0x50800000 at run time. That lies
> outside the 8 MiB reserved for SCP core0, so Linux is free to allocate
> over memory the firmware uses.
> 
> [...]

Applied to v7.3-next/dts64, thanks!

[1/1] arm64: dts: mediatek: mt8188-geralt: Enlarge SCP core0 memory region
      commit: 868297e3ebcc5c9b0e7cada19c82b11068faf4bf

Cheers,
Angelo

Re: [PATCH] arm64: dts: mediatek: mt8188-geralt: Enlarge SCP core0 memory region

Posted by Chen-Yu Tsai 1 month ago

On Mon, Aug 24, 2026 at 5:04 PM Justin Yeh <justin.yeh@mediatek.com> wrote:
>
> The SCP firmware in linux-firmware for this platform
> (mediatek/mt8188/scp_c0.img) supports MDP, which the mdp3-rdma node
> drives through scp_c0. On top of the segments it loads, the firmware
> allocates a 1 MiB DMA region at 0x50800000 at run time. That lies
> outside the 8 MiB reserved for SCP core0, so Linux is free to allocate
> over memory the firmware uses.
>
> Enlarge the region to 9 MiB. apu_mem starts at 0x55000000, so no other
> reserved region has to move.
>
> Fixes: e36be19823f0 ("arm64: dts: mediatek: mt8188-geralt: Enable first SCP core")
> Signed-off-by: Justin Yeh <justin.yeh@mediatek.com>

Reviewed-by: Chen-Yu Tsai <wenst@chromium.org>

> ---
>  arch/arm64/boot/dts/mediatek/mt8188-geralt.dtsi | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/arch/arm64/boot/dts/mediatek/mt8188-geralt.dtsi b/arch/arm64/boot/dts/mediatek/mt8188-geralt.dtsi
> index f382f90c48f5..35f60b5bba6f 100644
> --- a/arch/arm64/boot/dts/mediatek/mt8188-geralt.dtsi
> +++ b/arch/arm64/boot/dts/mediatek/mt8188-geralt.dtsi
> @@ -166,7 +166,7 @@ reserved_memory: reserved-memory {
>
>                 scp_mem_reserved: memory@50000000 {
>                         compatible = "shared-dma-pool";
> -                       reg = <0 0x50000000 0 0x800000>;
> +                       reg = <0 0x50000000 0 0x900000>;
>                         no-map;
>                 };
>
> --
> 2.45.2
>