[PATCH] arm64: dts: allwinner: a523: x96qpro+: overvolting eMMC

[PATCH] arm64: dts: allwinner: a523: x96qpro+: overvolting eMMC

[Andre Przywara]

On the X96QPro+ TV box, the eMMC wasn't working properly: the chip would
be detected, but most requests failed, leaving it unusable. Some
"solutions" were circulating downstream, one "popular" one is severely
limiting the clock frequency, with a drastic performance impact.

Instead slightly bumping the I/O voltage on PortC from the canonical
1.8V to 1.9V seemed to do the trick: the eMMC now works and reaches the
expected 120MB/s performance.

Adjust the respective regulator voltage in the .dts to enable eMMC
operation on that device.

Signed-off-by: Andre Przywara <andre.przywara@arm.com>
---
Hi,

I am not super happy with this patch, but it seems to be a pragmatic and
the least hacky solution I have seen.

Cheers,
Andre

 arch/arm64/boot/dts/allwinner/sun55i-h728-x96qpro+.dts | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/arch/arm64/boot/dts/allwinner/sun55i-h728-x96qpro+.dts b/arch/arm64/boot/dts/allwinner/sun55i-h728-x96qpro+.dts
index a96927fbdadd5..5636e95312218 100644
--- a/arch/arm64/boot/dts/allwinner/sun55i-h728-x96qpro+.dts
+++ b/arch/arm64/boot/dts/allwinner/sun55i-h728-x96qpro+.dts
@@ -194,8 +194,8 @@ reg_bldo4: bldo4 {
 
 			reg_cldo1: cldo1 {
 				regulator-always-on;
-				regulator-min-microvolt = <1800000>;
-				regulator-max-microvolt = <1800000>;
+				regulator-min-microvolt = <1900000>;
+				regulator-max-microvolt = <1900000>;
 				regulator-name = "vcc-codec-sd";
 			};
 
-- 
2.46.4