ARM: dts: meson8b: add reserved memory zone to fix silent freezes

So far, the stress-ng tool for instance quickly resulted in a silent
freeze of the system with no prior notice on a serial console when
running its filesystem or memory stressor classes.

Even with a panic-on-OOM and reboot-on-panic (vm.panic_on_oom=1,
kernel.panic=10) configured, the system would neither reboot nor
would the OOM killer get any chance to otherwise do its job.

The Amlogic reference source code uses a 2MB PHYS_OFFSET. With these 2MB
reserved via DT, stress-ng was able to run on an Odroid C1+ just fine for
several hours, the OOM killer was able to kill processes again and if
configured would successfully trigger a reboot of the system.

Fixes: 4a69fcd3a108 ("ARM: meson: Add DTS for Odroid-C1 and Tronfy MXQ boards")
Signed-off-by: Linus Lüssing <linus.luessing@c0d3.blue>
Acked-by: Martin Blumenstingl <martin.blumenstingl@googlemail.com>
Signed-off-by: Kevin Hilman <khilman@baylibre.com>

diff --git a/arch/arm/boot/dts/meson8b.dtsi b/arch/arm/boot/dts/meson8b.dtsi
index 274d5e4..bc4d4a2 100644 (file)
--- a/arch/arm/boot/dts/meson8b.dtsi
+++ b/arch/arm/boot/dts/meson8b.dtsi
@@ -83,6 +83,18 @@
                };
        };
 
+       reserved-memory {
+               #address-cells = <1>;
+               #size-cells = <1>;
+               ranges;
+
+               /* 2 MiB reserved for Hardware ROM Firmware? */
+               hwrom@0 {
+                       reg = <0x0 0x200000>;
+                       no-map;
+               };
+       };
+
        scu@c4300000 {
                compatible = "arm,cortex-a5-scu";
                reg = <0xc4300000 0x100>;