-----Original Message-----
From: Vladimir Oltean <vladimir.oltean@nxp.com>
Sent: Thursday, November 19, 2020 11:50 PM
To: Shawn Guo <shawnguo@kernel.org>; Leo Li <redacted>; Rob
Herring [off-list ref]; linux-arm-kernel@lists.infradead.org;
devicetree@vger.kernel.org
Cc: Adrian Hunter <adrian.hunter@intel.com>; Ulf Hansson
[off-list ref]; linux-mmc@vger.kernel.org;
linux-kernel@vger.kernel.org; Ashish Kumar [off-list ref]; Y.b. Lu
[off-list ref]; Michael Walle [off-list ref]
Subject: [PATCH] arm64: dts: ls1028a: make the eMMC and SD card
controllers use fixed indices

As the boot order in the kernel continues to change, sometimes it may
happen that the eSDHC controller mmc@2150000 (the one for eMMC) gets
probed before the one at mmc@2140000 (for external SD cards). The effect
is that the eMMC controller gets the /dev/mmcblk0 name, and the SD card
gets /dev/mmcblk1.

Since the introduction of this SoC, that has never happened in practice,
even though it was never guaranteed in theory. Setting
"root=/dev/mmcblk0p2" in /proc/cmdline has always caused the kernel to
use the second partition from the SD card as the rootfs.

Preserve that old behavior by adding some aliases which create naming
consistency:
- the SD card controller uses /dev/mmcblk0
- the eMMC controller uses /dev/mmcblk1

The aliases are parsed by mmc_alloc_host() in drivers/mmc/core/host.c.

Cc: Ashish Kumar <redacted>
Cc: Yangbo Lu <yangbo.lu@nxp.com>
Cc: Michael Walle <redacted>
Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com>
---
 arch/arm64/boot/dts/freescale/fsl-ls1028a-kontron-sl28.dts | 2 ++
 arch/arm64/boot/dts/freescale/fsl-ls1028a-qds.dts          | 2 ++
 arch/arm64/boot/dts/freescale/fsl-ls1028a-rdb.dts          | 2 ++
 3 files changed, 6 insertions(+)

diff --git a/arch/arm64/boot/dts/freescale/fsl-ls1028a-kontron-sl28.dts

b/arch/arm64/boot/dts/freescale/fsl-ls1028a-kontron-sl28.dts
index 8161dd237971..7d292999f8da 100644

--- a/arch/arm64/boot/dts/freescale/fsl-ls1028a-kontron-sl28.dts
+++ b/arch/arm64/boot/dts/freescale/fsl-ls1028a-kontron-sl28.dts

@@ -23,6 +23,8 @@ aliases {
 		serial2 = &lpuart1;
 		spi0 = &fspi;
 		spi1 = &dspi2;
+		mmc0 = &esdhc;
+		mmc1 = &esdhc1;
 	};

 	buttons0 {

diff --git a/arch/arm64/boot/dts/freescale/fsl-ls1028a-qds.dts

b/arch/arm64/boot/dts/freescale/fsl-ls1028a-qds.dts
index 13cdc958ba3e..c0786b713791 100644

--- a/arch/arm64/boot/dts/freescale/fsl-ls1028a-qds.dts
+++ b/arch/arm64/boot/dts/freescale/fsl-ls1028a-qds.dts

@@ -23,6 +23,8 @@ aliases {
 		gpio2 = &gpio3;
 		serial0 = &duart0;
 		serial1 = &duart1;
+		mmc0 = &esdhc;
+		mmc1 = &esdhc1;
 	};

 	chosen {

diff --git a/arch/arm64/boot/dts/freescale/fsl-ls1028a-rdb.dts

b/arch/arm64/boot/dts/freescale/fsl-ls1028a-rdb.dts
index 1efb61cff454..c1d1ba459307 100644

--- a/arch/arm64/boot/dts/freescale/fsl-ls1028a-rdb.dts
+++ b/arch/arm64/boot/dts/freescale/fsl-ls1028a-rdb.dts

@@ -19,6 +19,8 @@ aliases {
 		crypto = &crypto;
 		serial0 = &duart0;
 		serial1 = &duart1;
+		mmc0 = &esdhc;
+		mmc1 = &esdhc1;
 	};

 	chosen {
--

2.25.1