[U-Boot] [PATCH v7 2/3] mmc: meson: add MMC driver for Meson GX (S905)

[Andreas Färber]

Am 15.04.2017 um 23:04 schrieb Alexander Graf:
>> Am 15.04.2017 um 22:34 schrieb Andreas Färber <afaerber at suse.de>:
>>> Am 15.04.2017 um 20:27 schrieb Alexander Graf:
>>>> On 15.04.17 20:18, Heiner Kallweit wrote:
>>>>> Am 15.04.2017 um 17:05 schrieb Andreas Färber:
>>>>> But for the Vega S95 Telos I needed to disable the first of three MMC
>>>>> nodes (SDIO) - otherwise U-Boot would happily iterate over them for
>>>>> distro boot with Heinrich's patch, but GRUB would come up with no disks,
>>>>> so that booting failed. I'm not yet sure why, maybe it's a UEFI-side
>>>>> problem in that it is the first MMC device that is absent rather than
>>>>> the last one?
>>>>>
>>>> I don't own this device so I can just provide a guess.
>>>> Based on DT the device ordering most likely is:
>>>> mmc0: SDIO
>>>> mmc1: SD
>>>> mmc2: eMMC
>> [...]
>>> If grub comes up, distro boot has successfully found the target binary
>>> and executed it. For some reason, grub can not find its boot origin though.
>>>
>>> Andreas, please add debug prints like the ones below and check that the
>>> device names match:
>>
>> U-Boot 2017.05-rc1-00318-g082535f-dirty (Apr 15 2017 - 22:29:17 +0200)
>> vega-s95
>>
>> DRAM:  2 GiB
>> MMC:   mmc at 70000: 0, mmc at 72000: 1, mmc at 74000: 2
>> Using default environment
>>
>> In:    serial at 4c0
>> Out:   serial at 4c0
>> Err:   serial at 4c0
>> Net:   eth0: ethernet at c9410000
>> Hit any key to stop autoboot:  0
>> mmc_init: -95, time 1806
>> MMC Device 0 not found
>> no mmc device at slot 0
>> switch to partitions #0, OK
>> mmc1 is current device
>> Scanning mmc 1:1...
>> Setting boot device name to '//boot/dtb/amlogic/meson-gxbb-v'
>> 20335 bytes read in 43 ms (460.9 KiB/s)
>> Found EFI removable media binary efi/boot/bootaa64.efi
>> Setting boot device name to '/efi/boot/bootaa64.efi'
>> reading efi/boot/bootaa64.efi
>> 129024 bytes read in 13 ms (9.5 MiB/s)
>> ## Starting EFI application at 01080000 ...
>> mmc_init: -95, time 1807
>> Found 0 disks
> 
> That looks like efi_disk didn't manage to enumerate any devices?

Apparently. The last line comes from
lib/efi_loader_efi_disk:efi_disk_register(), and CONFIG_BLK=y. As you
can see, there is not a single "Scanning disk" line, so I guess we do
not iterate over uclass devices properly?

On the Odroid-C2 I get this:

Scanning disk mmc at 72000.blk...
Card did not respond to voltage select!
mmc_init: -95, time 9
Found 1 disks

Therefore my guess that it matters at what point in time - before or
after the disk we want - the error accessing an MMC device happens.

Regards,
Andreas

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