On Fri, Mar 2, 2018 at 5:27 PM, Sean Wang [off-list ref] wrote:

On Fri, 2018-03-02 at 09:42 -0600, Rob Herring wrote:

quoted

On Fri, Feb 23, 2018 at 06:16:36PM +0800, sean.wang at mediatek.com wrote:

quoted

From: Sean Wang <sean.wang@mediatek.com>

There is 2GB DDR3 available on bananapi-r2 board as [1] specified.

[1] http://www.banana-pi.org/r2.html

Signed-off-by: Sean Wang <sean.wang@mediatek.com>
---
 arch/arm/boot/dts/mt7623n-bananapi-bpi-r2.dts | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/arch/arm/boot/dts/mt7623n-bananapi-bpi-r2.dts b/arch/arm/boot/dts/mt7623n-bananapi-bpi-r2.dts
index 140ff78..3e8d02c 100644
--- a/arch/arm/boot/dts/mt7623n-bananapi-bpi-r2.dts
+++ b/arch/arm/boot/dts/mt7623n-bananapi-bpi-r2.dts

@@ -38,6 +38,11 @@
                    default-state = "off";
            };
    };
+
+   memory {

Unit address?

If I did it with adding unit address

-       memory {
+       memory at 80000000 {
                device_type = "memory";
                reg = <0 0x80000000 0 0x80000000>;
        };


bad dtc blob is being generated and contains two memory nodes, one is
memory and the other is memory at 80000000 whose blob disassembly detail is
as the following.

      memory {
                device_type = "memory";
                reg = <0x0 0x0 0x0 0x0>;
        };



      memory at 80000000 {
                device_type = "memory";
                reg = <0x0 0x80000000 0x0 0x80000000>;
        };


and bad memory node with size 0 would cause the boot fails.


is it a dtc compiler problem ?

No, you are declaring "memory" node somewhere else. Perhaps using
skeleton.dtsi which we are trying to remove or you have some default.

Using just 'memory' is fine if the base address is variable and
determined at boot time or you have a bootloader that expects just
'memory'. Otherwise, this should be fixed, but you can do that after
this patch if you want.

Rob