[U-Boot] Falcon boot breaks on DRA7 because of commit b9c8ccab "env_mmc.c: Allow environment to be used within SPL"

[Jean-Jacques Hiblot]

On 24/01/2017 16:46, Tom Rini wrote:
>> I had noticed that it's quite old indeed. I didn't mean that it's a
>> regression. I'm just puzzled by the commit. what is its purpose ?
>> why is SPL not using  CONFIG_SYS_MMC_ENV_DEV ?
> Because in SPL we do not have both MMC devices initialized.
That is not always the case. Actually in spl_mmc.c the code requires us 
to register more than one MMC device to work properly when multiple MMC 
boot devices can be used (see spl_mmc_get_device_index())
I did the test of registering only MMC2 when booting from eMMC, the SPL 
fails because it can't find device 1:
Trying to boot from MMC2_2
MMC Device 1 not found
spl: could not find mmc device. error: -19

> We register
> the one we booted from and thus it is device 0 to U-Boot in this case.
> I suspect the rest of the issues stem from this quirk, or something
> having broken around this quirk.  Thanks!