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

[Alexander Graf <agraf@suse.de>]

On 16.04.17 04:09, Heinrich Schuchardt wrote:
> On 04/15/2017 11:51 PM, Andreas F채rber wrote:
>> Am 15.04.2017 um 23:16 schrieb Andreas F채rber:
>>> Am 15.04.2017 um 23:04 schrieb Alexander Graf:
>>>>> Am 15.04.2017 um 22:34 schrieb Andreas F채rber <afaerber@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 F채rber:
>>>>>>>> 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.
>>
>> For comparison, Vega S95 with first MMC node disabled in DT:
>>
>> Scanning disk mmc at 72000.blk...
>> Adding disk device 'mmc at 72000.blk'
>> ** First descriptor is NOT a primary desc on 1:1 **
>> Scanning disk mmc at 74000.blk...
>> Adding disk device 'mmc at 74000.blk'
>> Found 2 disks
>>
>> Regards,
>> Andreas
>>
> By adding sd_mmc_a to the odroid-c2.dts I was able to reproduce the
> problem on the Odroid C2.
>
> While booting from SD card via booti still worked
> bootefi would not find any block device:
>
> => bootefi hello
> ## Starting EFI application at 01000000 ...
> WARNING: Invalid device tree, expect boot to fail
> efi_add_memory_map: 0x7cf53000 0x1 2 yes
> uclass_find_device_by_seq: 0 -1
> uclass_find_device_by_seq: 0 0
>    - -1 -1
>    - -1 -1
>    - -1 -1
>    - not found
> set_state_simple op missing
> blk_get_device: if_type=6, devnum=0: mmc at 70000.blk, 6, 0
> mmc_init: -95, time 1807
> Found 0 disks
> efi_add_memory_map: 0x7cf52000 0x1 6 yes
> do_bootefi_exec:234 Jumping to 0x7cf53148
> EFI: Entry efi_cout_output_string(000000007ff94b38, 000000007cf53280)
> Hello, world!
> EFI: Entry efi_exit(000000007ffa4598, 0, 0, 0000000000000000)
> ## Application terminated, r = 0
>
> In the debug output you can see that after trying non-existant
> mmc at 70000.blk no further devices are scanned. mmc at 72000.blk which has
> the SD card is not enumerated.

To me that looks like something wrong with DM code, as there is no 
explicit abort condition in efi_disk_register() for the CONFIG_BLK case. 
Let's CC Simon and ask for help :).


Alex