diff --git a/arch/arm64/boot/dts/renesas/r9a09g077m44-rzt2h-evk.dts b/arch/arm64/boot/dts/renesas/r9a09g077m44-rzt2h-evk.dts
index b7706d0bc3aa..d1474f1bd523 100644
--- a/arch/arm64/boot/dts/renesas/r9a09g077m44-rzt2h-evk.dts
+++ b/arch/arm64/boot/dts/renesas/r9a09g077m44-rzt2h-evk.dts
@@ -26,6 +26,9 @@
  * P17_4 = SD1_CD; SW2[3] = ON
  * P08_5 = SD1_PWEN; SW2[3] = ON
  * P08_6 = SD1_IOVS; SW2[3] = ON; SW5[3] = OFF; SW5[4] = ON
+ * To enable proper operation in 1.8V modes, CN77 must have pins 2 and 3
+ * connected by the jumper. This connects SD1 power-supply control IC output
+ * back to VCC1833_7.
  */
 #define SD1_MICRO_SD	1
 
diff --git a/arch/arm64/boot/dts/renesas/r9a09g087m44-rzn2h-evk.dts b/arch/arm64/boot/dts/renesas/r9a09g087m44-rzn2h-evk.dts
index 17c0c79fbd96..eaf73868783b 100644
--- a/arch/arm64/boot/dts/renesas/r9a09g087m44-rzn2h-evk.dts
+++ b/arch/arm64/boot/dts/renesas/r9a09g087m44-rzn2h-evk.dts
@@ -30,6 +30,9 @@
 /*
  * P17_4 = SD1_CD; DSW5[3] = ON; DSW19[1] = OFF; DSW19[2] = ON
  * P08_6 = SD1_IOVS; DSW5[3] = ON
+ * To enable proper operation in 1.8V modes, JP21 must have pins 2 and 3
+ * connected by the jumper. This connects SD1 power-supply control IC output
+ * back to VCC1833_7.
  */
 #define SD1_MICRO_SD	1