From:   Robert Marko <robert.marko@sartura.hr>
To:     robh+dt@kernel.org, krzysztof.kozlowski+dt@linaro.org,
        lars.povlsen@microchip.com, Steen.Hegelund@microchip.com,
        daniel.machon@microchip.com, UNGLinuxDriver@microchip.com,
        arnd@arndb.de, alexandre.belloni@bootlin.com,
        devicetree@vger.kernel.org, linux-arm-kernel@lists.infradead.org,
        linux-kernel@vger.kernel.org
Cc:     luka.perkov@sartura.hr, Robert Marko <robert.marko@sartura.hr>
Subject: [PATCH v2 1/3] arm64: dts: microchip: sparx5: do not use PSCI on reference boards
Date:   Tue, 21 Feb 2023 11:50:37 +0100
Message-Id: <20230221105039.316819-1-robert.marko@sartura.hr>
MIME-Version: 1.0
Content-Transfer-Encoding: 8bit
Precedence: bulk

PSCI is not implemented on SparX-5 at all, there is no ATF and U-boot that
is shipped does not implement it as well.

I have tried flashing the latest BSP 2022.12 U-boot which did not work.
After contacting Microchip, they confirmed that there is no ATF for the
SoC nor PSCI implementation which is unfortunate in 2023.

So, disable PSCI as otherwise kernel crashes as soon as it tries probing
PSCI with, and the crash is only visible if earlycon is used.

Since PSCI is not implemented, switch core bringup to use spin-tables
which are implemented in the vendor U-boot and actually work.

Tested on PCB134 with eMMC (VSC5640EV).

Fixes: 6694aee00a4b ("arm64: dts: sparx5: Add basic cpu support")
Signed-off-by: Robert Marko <robert.marko@sartura.hr>
---
Changes in v2:
* As suggested by Arnd, disable PSCI only on reference boards
---
 arch/arm64/boot/dts/microchip/sparx5.dtsi            |  2 +-
 arch/arm64/boot/dts/microchip/sparx5_pcb_common.dtsi | 12 ++++++++++++
 2 files changed, 13 insertions(+), 1 deletion(-)

diff --git a/arch/arm64/boot/dts/microchip/sparx5.dtsi b/arch/arm64/boot/dts/microchip/sparx5.dtsi
index 0367a00a269b3..5eae6e7fd248e 100644
--- a/arch/arm64/boot/dts/microchip/sparx5.dtsi
+++ b/arch/arm64/boot/dts/microchip/sparx5.dtsi
@@ -61,7 +61,7 @@ arm-pmu {
 		interrupt-affinity = <&cpu0>, <&cpu1>;
 	};
 
-	psci {
+	psci: psci {
 		compatible = "arm,psci-0.2";
 		method = "smc";
 	};
diff --git a/arch/arm64/boot/dts/microchip/sparx5_pcb_common.dtsi b/arch/arm64/boot/dts/microchip/sparx5_pcb_common.dtsi
index 9d1a082de3e29..32bb76b3202a0 100644
--- a/arch/arm64/boot/dts/microchip/sparx5_pcb_common.dtsi
+++ b/arch/arm64/boot/dts/microchip/sparx5_pcb_common.dtsi
@@ -6,6 +6,18 @@
 /dts-v1/;
 #include "sparx5.dtsi"
 
+&psci {
+	status = "disabled";
+};
+
+&cpu0 {
+	enable-method = "spin-table";
+};
+
+&cpu1 {
+	enable-method = "spin-table";
+};
+
 &uart0 {
 	status = "okay";
 };
-- 
2.39.2