From 050f43fa24de492ef4a0740871edfa52a30c8338 Mon Sep 17 00:00:00 2001 From: Stefan Agner Date: Wed, 13 Sep 2017 14:29:45 -0700 Subject: [PATCH] imx_common: detect USB serial downloader reliably The current mechanism using SCR/GPR registers work well when the serial downloader boot mode has been selected explicitly (either via boot mode pins or using bmode command). However, in case the system entered boot ROM due to unbootable primary boot devices (e.g. empty eMMC), the SPL fails to detect that it has been downloaded through serial loader and tries to continue booting from eMMC: Trying to boot from MMC1 mmc_load_image_raw_sector: mmc block read error SPL: failed to boot from all boot devices ### ERROR ### Please RESET the board ### The only known way to reliably detect USB serial downloader is by checking the USB PHY receiver block power state... Signed-off-by: Stefan Agner Acked-by: Marcel Ziswiler Tested-by: Fabio Estevam Reviewed-by: Eric Nelson --- arch/arm/mach-imx/spl.c | 12 ++++++++++++ 1 file changed, 12 insertions(+) diff --git a/arch/arm/mach-imx/spl.c b/arch/arm/mach-imx/spl.c index 258578ac25..82ea6b85d6 100644 --- a/arch/arm/mach-imx/spl.c +++ b/arch/arm/mach-imx/spl.c @@ -31,6 +31,18 @@ u32 spl_boot_device(void) if (((bmode >> 24) & 0x03) == 0x01) /* Serial Downloader */ return BOOT_DEVICE_BOARD; + /* + * The above method does not detect that the boot ROM used + * serial downloader in case the boot ROM decided to use the + * serial downloader as a fall back (primary boot source failed). + * + * Infer that the boot ROM used the USB serial downloader by + * checking whether the USB PHY is currently active... This + * assumes that SPL did not (yet) initialize the USB PHY... + */ + if (is_usbotg_phy_active()) + return BOOT_DEVICE_BOARD; + /* BOOT_CFG1[7:4] - see IMX6DQRM Table 8-8 */ switch ((reg & IMX6_BMODE_MASK) >> IMX6_BMODE_SHIFT) { /* EIM: See 8.5.1, Table 8-9 */ -- 2.39.5