On 11/11/2022 10:55, Macpaul Lin wrote:

The size of device tree node secmon (bl31_secmon_reserved) was incorrect. It should be increased to 2MiB (0x200000).

The origin setting will cause some abnormal behavior due to trusted-firmware-a and related firmware didn't load correctly. The incorrect behavior may vary because of different software stacks. For example, it will cause build error in some Yocto project because it will check if there was enough memory to load trusted-firmware-a to the reserved memory.

When mt8195-demo.dts sent to the upstream, at that time the size of BL31 was small. Because supported functions and modules in BL31 are basic sets when the board was under early development stage.

Now BL31 includes more firmwares of coprocessors and maturer functions so the size has grown bigger in real applications. According to the value reported by customers, we think reserved 2MiB for BL31 might be enough for maybe the following 2 or 3 years.

Cc: stable@vger.kernel.org # v5.19 Fixes: 6147314aeedc ("arm64: dts: mediatek: Add device-tree for MT8195 Demo board") Signed-off-by: Macpaul Lin macpaul.lin@mediatek.com Reviewed-by: Miles Chen miles.chen@mediatek.com

Applied now to v6.1-next/fixes

Thanks!

---

Changes for v2

• Add more information about the size difference for BL31 in commit message. Thanks for Miles's review.

arch/arm64/boot/dts/mediatek/mt8195-demo.dts | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/arch/arm64/boot/dts/mediatek/mt8195-demo.dts b/arch/arm64/boot/dts/mediatek/mt8195-demo.dts index 4fbd99eb496a..dec85d254838 100644 --- a/arch/arm64/boot/dts/mediatek/mt8195-demo.dts +++ b/arch/arm64/boot/dts/mediatek/mt8195-demo.dts @@ -56,10 +56,10 @@ #size-cells = <2>; ranges;

• /* 192 KiB reserved for ARM Trusted Firmware (BL31) */
  

• /* 2 MiB reserved for ARM Trusted Firmware (BL31) */
  

  bl31_secmon_reserved: secmon@54600000 { no-map;

• 	reg = <0 0x54600000 0x0 0x30000>;
  

• 	reg = <0 0x54600000 0x0 0x200000>;
  

  };

/* 12 MiB reserved for OP-TEE (BL32)