[U-Boot] [PATCH] mmc: Downgrade SD/MMC from UHS/HS200/HS400 modes before boot

[Faiz Abbas]

Hi,

On 14/02/19 6:56 PM, Marek Vasut wrote:
> Older kernel versions or systems which do not connect eMMC reset line
> properly may not be able to handle situations where either the eMMC
> is left in HS200/HS400 mode or SD card in UHS modes by the bootloader
> and may misbehave. Downgrade the eMMC to HS/HS52 mode and/or SD card
> to non-UHS mode before booting the kernel to allow such older kernels
> to work with modern U-Boot.

This broke boot on all dra7xx devices. The fallback to DDR52 doesn't go
through and all following commands timeout.

Log:

U-Boot 2019.04-rc4-00018-ga00d15757d (Mar 20 2019 - 17:25:22 +0200)

CPU  : DRA752-GP ES2.0
Model: TI DRA742
Board: DRA74x EVM REV H.0
DRAM:  4 GiB
MMC:   OMAP SD/MMC: 0, OMAP SD/MMC: 1
Loading Environment from FAT... *** Warning - bad CRC, using default
environment

Loading Environment from MMC... OK
Net:   eth0: ethernet at 48484000
Hit any key to stop autoboot:  0
=>
=> boot
Booting from network ...
link up on port 0, speed 1000, full duplex
BOOTP broadcast 1
DHCP client bound to address 192.168.1.52 (246 ms)
link up on port 0, speed 1000, full duplex
Using ethernet at 48484000 device
TFTP from server 192.168.1.36; our IP address is 192.168.1.52
Filename 'zImage'.
Load address: 0x87000000
Loading: #################################################################
         #################################################################
         #################################################################
         #################################################################
         #################################################################
         #################################################################
         #################################################################
         #################################################################
         #################################################################
         #################################################################
         #############################################
         3.3 MiB/s
done
Bytes transferred = 3556144 (364330 hex)
link up on port 0, speed 1000, full duplex
Using ethernet at 48484000 device
TFTP from server 192.168.1.36; our IP address is 192.168.1.52
Filename 'dra7-evm.dtb'.
Load address: 0x88000000
Loading: ######################
         2.9 MiB/s
done
Bytes transferred = 108307 (1a713 hex)
## Flattened Device Tree blob at 88000000
   Booting using the fdt blob at 0x88000000
   Loading Device Tree to 8ffe2000, end 8ffff712 ... OK
Using machid 0xfe6 from environment

Starting kernel ...

omap_hsmmc_send_cmd: timedout waiting on cmd inhibit to clear
omap_hsmmc_send_cmd: timedout waiting on cmd inhibit to clear
omap_hsmmc_send_cmd: timedout waiting on cmd inhibit to clear
omap_hsmmc_send_cmd: timedout waiting on cmd inhibit to clear
omap_hsmmc_send_cmd: timedout waiting on cmd inhibit to clear
omap_hsmmc_send_cmd: timedout waiting on cmd inhibit to clear
omap_hsmmc_send_cmd: timedout waiting on cmd inhibit to clear
omap_hsmmc_send_cmd: timedout waiting on cmd inhibit to clear
omap_hsmmc_send_cmd: timedout waiting on cmd inhibit to clear
omap_hsmmc_send_cmd: timedout waiting on cmd inhibit to clear

Thanks,
Faiz