Patch "arm64: dts: microchip: sparx5: do not use PSCI on reference boards" has been added to the 5.15-stable tree

[Sasha Levin <sashal@xxxxxxxxxx>]

This is a note to let you know that I've just added the patch titled

    arm64: dts: microchip: sparx5: do not use PSCI on reference boards

to the 5.15-stable tree which can be found at:
    http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary

The filename of the patch is:
     arm64-dts-microchip-sparx5-do-not-use-psci-on-refere.patch
and it can be found in the queue-5.15 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.



commit c9825c93f372db37e5484336b5831904997363cd
Author: Robert Marko <robert.marko@xxxxxxxxxx>
Date:   Tue Feb 21 11:50:37 2023 +0100

    arm64: dts: microchip: sparx5: do not use PSCI on reference boards
    
    [ Upstream commit 70be83708c925b3f72c508e4756e48ad2330c830 ]
    
    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@xxxxxxxxxx>
    Acked-by: Steen Hegelund <Steen.Hegelund@xxxxxxxxxxxxx>
    Link: https://lore.kernel.org/r/20230221105039.316819-1-robert.marko@xxxxxxxxxx
    Signed-off-by: Krzysztof Kozlowski <krzysztof.kozlowski@xxxxxxxxxx>
    Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>

diff --git a/arch/arm64/boot/dts/microchip/sparx5.dtsi b/arch/arm64/boot/dts/microchip/sparx5.dtsi
index 787ebcec121d6..a6405059636c3 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";
 };