[PATCH v2] arm64: dts: mediatek: mt8195-demo: fix the memory size of node secmon

[Macpaul Lin]

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 at vger.kernel.org      # v5.19
Fixes: 6147314aeedc ("arm64: dts: mediatek: Add device-tree for MT8195 Demo board")
Signed-off-by: Macpaul Lin <macpaul.lin at mediatek.com>
Reviewed-by: Miles Chen <miles.chen at mediatek.com>
---
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 at 54600000 {
 			no-map;
-			reg = <0 0x54600000 0x0 0x30000>;
+			reg = <0 0x54600000 0x0 0x200000>;
 		};
 
 		/* 12 MiB reserved for OP-TEE (BL32)
-- 
2.18.0