Patch "arm64: dts: allwinner: A64: Limit MMC2 bus frequency to 150 MHz" has been added to the 5.4-stable tree

[Sasha Levin <sashal@xxxxxxxxxx>]

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

    arm64: dts: allwinner: A64: Limit MMC2 bus frequency to 150 MHz

to the 5.4-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-allwinner-a64-limit-mmc2-bus-frequency-to-.patch
and it can be found in the queue-5.4 subdirectory.

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



commit a0a0a2efd49bb90549b45f3e9806ea5562fac41b
Author: Andre Przywara <andre.przywara@xxxxxxx>
Date:   Wed Jan 13 15:26:28 2021 +0000

    arm64: dts: allwinner: A64: Limit MMC2 bus frequency to 150 MHz
    
    [ Upstream commit 948c657cc45e8ce48cb533d4e2106145fa765759 ]
    
    In contrast to the H6 (and later) manuals, the A64 datasheet does not
    specify any limitations in the maximum possible frequency for eMMC
    controllers.
    However experimentation has found that a 150 MHz limit similar to other
    SoCs and also the MMC0 and MMC1 controllers on the A64 seems to exist
    for the MMC2 controller.
    
    Limit the frequency for the MMC2 controller to 150 MHz in the SoC .dtsi.
    The Pinebook seems to be the an odd exception, since it apparently seems
    to work with 200 MHz as well, so overwrite this in its board .dts file.
    
    Tested on a Pine64-LTS: 200 MHz HS-200 fails, 150 MHz HS-200 works.
    
    Fixes: 22be992faea7 ("arm64: allwinner: a64: Increase the MMC max frequency")
    Signed-off-by: Andre Przywara <andre.przywara@xxxxxxx>
    Acked-by: Chen-Yu Tsai <wens@xxxxxxxx>
    Signed-off-by: Maxime Ripard <maxime@xxxxxxxxxx>
    Link: https://lore.kernel.org/r/20210113152630.28810-7-andre.przywara@xxxxxxx
    Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>

diff --git a/arch/arm64/boot/dts/allwinner/sun50i-a64-pinebook.dts b/arch/arm64/boot/dts/allwinner/sun50i-a64-pinebook.dts
index b0f81802d334b..bb1de8217b86d 100644
--- a/arch/arm64/boot/dts/allwinner/sun50i-a64-pinebook.dts
+++ b/arch/arm64/boot/dts/allwinner/sun50i-a64-pinebook.dts
@@ -140,6 +140,7 @@
 	pinctrl-0 = <&mmc2_pins>, <&mmc2_ds_pin>;
 	vmmc-supply = <&reg_dcdc1>;
 	vqmmc-supply = <&reg_eldo1>;
+	max-frequency = <200000000>;
 	bus-width = <8>;
 	non-removable;
 	cap-mmc-hw-reset;
diff --git a/arch/arm64/boot/dts/allwinner/sun50i-a64.dtsi b/arch/arm64/boot/dts/allwinner/sun50i-a64.dtsi
index 4c85dfc811c80..cf9e3234afaf8 100644
--- a/arch/arm64/boot/dts/allwinner/sun50i-a64.dtsi
+++ b/arch/arm64/boot/dts/allwinner/sun50i-a64.dtsi
@@ -476,7 +476,7 @@
 			resets = <&ccu RST_BUS_MMC2>;
 			reset-names = "ahb";
 			interrupts = <GIC_SPI 62 IRQ_TYPE_LEVEL_HIGH>;
-			max-frequency = <200000000>;
+			max-frequency = <150000000>;
 			status = "disabled";
 			#address-cells = <1>;
 			#size-cells = <0>;