On Friday, December 9, 2022 6:01:13 A.M. EST Peter Robinson wrote:
On Thu, Dec 8, 2022 at 3:23 PM Detlev Casanova
detlev.casanova@collabora.com wrote:
In commit d0399a46e7cda63c07e3eb8558bef84cfb068028, the device tree was synchronized from linux and the aliases were dropped.
Is there a reason not to get this change upstreamed in to Linux and then this wouldn't be a problem moving forward?
Yes, please check this conversation: http://patchwork.ozlabs.org/comment/3016037/%5B1]
They need to be kept so that the mmc cards are in the right order. Without the aliases, u-boot reports: MMC: FSL_SDHC: 2, FSL_SDHC: 3
With the aliases, u-boot reports: MMC: FSL_SDHC: 0, FSL_SDHC: 1
The upstream linux device tree does not contain the same aliases than u-boot (It keeps the devices order with /dev/mmcblk2 and /dev/mmcblk3). Because this board has been using different aliases in u-boot and linux, a imx6q-sabrelite-u-boot.dtsi file is added to be automatically included in imx6q-sabrelite.dts.
This way, linux and u-boot each keep their own aliases and there is no breakage on current installations.
This should never be done for new boards as we want to keep linux and u-boot with the same aliases as much as possible. This patch is only necessary to avoid breaking existing setups.
Signed-off-by: Detlev Casanova detlev.casanova@collabora.com
Gbp-Pq: Topic apertis/imx6 Gbp-Pq: Name 0010-imx6-Re-add-mmc-aliases.patch
arch/arm/dts/imx6q-sabrelite-u-boot.dtsi | 15 +++++++++++++++ 1 file changed, 15 insertions(+) create mode 100644 arch/arm/dts/imx6q-sabrelite-u-boot.dtsi
diff --git a/arch/arm/dts/imx6q-sabrelite-u-boot.dtsi b/arch/arm/dts/imx6q-sabrelite-u-boot.dtsi new file mode 100644 index 0000000000..706ec9ba25 --- /dev/null +++ b/arch/arm/dts/imx6q-sabrelite-u-boot.dtsi @@ -0,0 +1,15 @@ +// SPDX-License-Identifier: GPL-2.0+ +/*
- Copyright (C) 2022 Collabora
- */
+#include "imx6qdl-u-boot.dtsi"
+/ {
aliases {mmc0 = &usdhc3;mmc1 = &usdhc4;pwm_lcd = &pwm1;pwm_lvds = &pwm4;};+};
2.38.1
-------- [1] http://patchwork.ozlabs.org/comment/3016037/