diff --git a/devices/asus-dumo/kernel/0001-HACK-disables-hs400es-codepath.patch b/devices/asus-dumo/kernel/0001-HACK-disables-hs400es-codepath.patch
deleted file mode 100644
index 27d9d1b29..000000000
--- a/devices/asus-dumo/kernel/0001-HACK-disables-hs400es-codepath.patch
+++ /dev/null
@@ -1,31 +0,0 @@
-From c17ac107ca60bea6bccd7acefe25104dca9923dc Mon Sep 17 00:00:00 2001
-From: Samuel Dionne-Riel <samuel@dionne-riel.com>
-Date: Thu, 12 Sep 2019 15:40:28 -0400
-Subject: [PATCH] HACK: disables hs400es codepath
-
-This is NOT a good fix. This is only to make the device usable
-for testing purposes.
-
----
- drivers/mmc/core/mmc.c | 4 ++--
- 1 file changed, 2 insertions(+), 2 deletions(-)
-
-diff --git a/drivers/mmc/core/mmc.c b/drivers/mmc/core/mmc.c
-index c8804895595f..525b90de160d 100644
---- a/drivers/mmc/core/mmc.c
-+++ b/drivers/mmc/core/mmc.c
-@@ -1500,9 +1500,9 @@ static int mmc_select_timing(struct mmc_card *card)
- 	if (!mmc_can_ext_csd(card))
- 		goto bus_speed;
- 
--	if (card->mmc_avail_type & EXT_CSD_CARD_TYPE_HS400ES)
-+	/*if (card->mmc_avail_type & EXT_CSD_CARD_TYPE_HS400ES)
- 		err = mmc_select_hs400es(card);
--	else if (card->mmc_avail_type & EXT_CSD_CARD_TYPE_HS200)
-+	else */if (card->mmc_avail_type & EXT_CSD_CARD_TYPE_HS200)
- 		err = mmc_select_hs200(card);
- 	else if (card->mmc_avail_type & EXT_CSD_CARD_TYPE_HS)
- 		err = mmc_select_hs(card);
--- 
-2.19.2
-
diff --git a/devices/asus-dumo/kernel/0001-gru-Force-hs200-for-eMMC.patch b/devices/asus-dumo/kernel/0001-gru-Force-hs200-for-eMMC.patch
new file mode 100644
index 000000000..efe0d6c75
--- /dev/null
+++ b/devices/asus-dumo/kernel/0001-gru-Force-hs200-for-eMMC.patch
@@ -0,0 +1,35 @@
+From bc25983bc1efb11656f7b9951de979e1959e8eef Mon Sep 17 00:00:00 2001
+From: Samuel Dionne-Riel <samuel@dionne-riel.com>
+Date: Fri, 24 Jan 2020 19:17:12 -0500
+Subject: [PATCH] gru: Force hs200 for eMMC
+
+hs400, at least on gru-dumo, a gru-scarlet, fails.
+---
+ arch/arm64/boot/dts/rockchip/rk3399-gru.dtsi | 10 +---------
+ 1 file changed, 1 insertion(+), 9 deletions(-)
+
+diff --git a/arch/arm64/boot/dts/rockchip/rk3399-gru.dtsi b/arch/arm64/boot/dts/rockchip/rk3399-gru.dtsi
+index dd5624975c9b4..1221894c54977 100644
+--- a/arch/arm64/boot/dts/rockchip/rk3399-gru.dtsi
++++ b/arch/arm64/boot/dts/rockchip/rk3399-gru.dtsi
+@@ -490,16 +490,8 @@ ap_i2c_audio: &i2c8 {
+ };
+ 
+ &sdhci {
+-	/*
+-	 * Signal integrity isn't great at 200 MHz and 150 MHz (DDR) gives the
+-	 * same (or nearly the same) performance for all eMMC that are intended
+-	 * to be used.
+-	 */
+-	assigned-clock-rates = <150000000>;
+-
+ 	bus-width = <8>;
+-	mmc-hs400-1_8v;
+-	mmc-hs400-enhanced-strobe;
++	mmc-hs200-1_8v;
+ 	non-removable;
+ 	status = "okay";
+ };
+-- 
+2.23.1
+
diff --git a/devices/asus-dumo/kernel/default.nix b/devices/asus-dumo/kernel/default.nix
index 56c8a29fb..bd85deaa3 100644
--- a/devices/asus-dumo/kernel/default.nix
+++ b/devices/asus-dumo/kernel/default.nix
@@ -6,7 +6,7 @@
 }:
 
 (mobile-nixos.kernel-builder {
-  version = "5.3.0";
+  version = "5.5.0";
   configfile = ./config.aarch64;
 
   hasDTB = true;
@@ -14,12 +14,12 @@
   src = fetchFromGitHub {
     owner = "torvalds";
     repo = "linux";
-    rev = "v5.3";
-    sha256 = "1iiv8fim1l4n7n7wkq0x4bf84ygrd1i7zaybmsphswsx1cpb5g6j";
+    rev = "v5.5";
+    sha256 = "0d35pdi1mjl4rj79da5fr21jhwrx742xf8a45mkx3dlg7cbn4gnk";
   };
 
   patches = [
-    ./0001-HACK-disables-hs400es-codepath.patch
+    ./0001-gru-Force-hs200-for-eMMC.patch
   ];
 
   isModular = false;