[PATCH] arm: imx: imx9: scmi: Fix booting from USB

[Peng Fan]

On Tue, Jul 22, 2025 at 11:04:45AM -0300, João Paulo Gonçalves wrote:
>From: João Paulo Gonçalves <joao.goncalves at toradex.com>
>
>On i.MX95, when booting from USB, the U-Boot environment is always
>assumed to be in RAM. However, this causes the boot to hang when
>`CONFIG_ENV_IS_NOWHERE` is not enabled. The boot also hangs even if the
>environment is present in another storage media (for example, eMMC). Fix
>the issue by correctly handling the U-Boot environment's location when
>booting from USB. Also, set the environment location based on the ENV
>config and not solely based on the boot device type.
>
>---
>Hello all,
>
>The change was not tested on mainline, but with downstream
>`toradex_imx_lf_v2024.04` U-Boot branch. In the past, i.MX8M had the
>same problem and the solution was similar.
>
>Best Regards,
>João Paulo Gonçalves
>---
> arch/arm/mach-imx/imx9/scmi/soc.c | 14 +++++++++++---
> 1 file changed, 11 insertions(+), 3 deletions(-)
>
>diff --git a/arch/arm/mach-imx/imx9/scmi/soc.c b/arch/arm/mach-imx/imx9/scmi/soc.c
>index 13f13ca7d1056ac5a9f1b529b13e0d8dbe2462f1..2c052c38521793e1f6ab2dc5125afa3b5ca63d0f 100644
>--- a/arch/arm/mach-imx/imx9/scmi/soc.c
>+++ b/arch/arm/mach-imx/imx9/scmi/soc.c
>@@ -633,9 +633,13 @@ enum env_location env_get_location(enum env_operation op, int prio)
> 	if (prio)
> 		return env_loc;
> 
>+	if (IS_ENABLED(CONFIG_ENV_IS_NOWHERE))
>+		env_loc = ENVL_NOWHERE;
>+
> 	switch (dev) {
> 	case QSPI_BOOT:
>-		env_loc = ENVL_SPI_FLASH;
>+		if (IS_ENABLED(CONFIG_ENV_IS_IN_SPI_FLASH))
>+			env_loc = ENVL_SPI_FLASH;
> 		break;
> 	case SD1_BOOT:
> 	case SD2_BOOT:
>@@ -643,10 +647,14 @@ enum env_location env_get_location(enum env_operation op, int prio)
> 	case MMC1_BOOT:
> 	case MMC2_BOOT:
> 	case MMC3_BOOT:
>-		env_loc =  ENVL_MMC;
>+		if (IS_ENABLED(CONFIG_ENV_IS_IN_MMC))
>+			env_loc =  ENVL_MMC;
> 		break;
> 	default:
>-		env_loc = ENVL_NOWHERE;
>+		if (IS_ENABLED(CONFIG_ENV_IS_IN_SPI_FLASH))
>+			env_loc = ENVL_SPI_FLASH;
>+		else if (IS_ENABLED(CONFIG_ENV_IS_IN_MMC))
>+			env_loc = ENVL_MMC;

If boot from USB, this means env_loc will be override here.

NXP boards always use RAM env when booting from USB.
If your boards has different settings, I think we may need to
introduce board_env_get_location. Or add some device tree
properties to specify the env settings.

Thanks,
Peng

> 		break;
> 	}
> 
>
>---
>base-commit: bd0ade7d090a334b3986936d63a34001d99722ad
>change-id: 20250722-v1-fix-imx95-usb-boot-9e6d760be10e
>
>Best regards,
>-- 
>João Paulo Gonçalves <joao.goncalves at toradex.com>
>