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

[Marek Vasut]

On 5/2/19 9:57 AM, Faiz Abbas wrote:
> Hi,

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

This seems to be a kernel bug ?

-- 
Best regards,
Marek Vasut