[U-Boot] ZynqMP breakage

[Alexander Graf]

On 09/06/2016 02:52 PM, Simon Glass wrote:
> Hi Alex,
>
> On 6 September 2016 at 03:09, Alexander Graf <agraf at suse.de> wrote:
>> On 09/06/2016 03:05 AM, Simon Glass wrote:
>>> Hi Alex,
>>>
>>> On 5 September 2016 at 04:51, Alexander Graf <agraf at suse.de> wrote:
>>>> On 08/19/2016 08:45 AM, Michal Simek wrote:
>>>>> On 16.8.2016 20:39, Alexander Graf wrote:
>>>>>> Hi Michal,
>>>>>>
>>>>>> I just tried to run the latest u-boot master + a few patches to
>>>>>> implement
>>>>>> generic PSCI RTS support on zynqmp and got this:
>>>>>>
>>>>>> e
>>>>>> U-Boot 2016.09-rc1-00453-ga0592f1 (Aug 16 2016 - 20:27:40 +0200) Xilinx
>>>>>> ZynqMP ZCU102
>>>>>>
>>>>>> I2C:   ready
>>>>>> DRAM:  4 GiB
>>>>>> EL Level:       EL2
>>>>>> MMC:   sdhci at ff170000: 0
>>>>>> Using default environment
>>>>>>
>>>>>> In:    serial at ff000000
>>>>>> Out:   serial at ff000000
>>>>>> Err:   serial at ff000000
>>>>>> Bootmode: SD_MODE1
>>>>>> SCSI:  SATA link 0 timeout.
>>>>>> Target spinup took 0 ms.
>>>>>> AHCI 0001.0301 32 slots 2 ports 6 Gbps 0x3 impl SATA mode
>>>>>> flags: 64bit ncq pm clo only pmp fbss pio slum part ccc apst
>>>>>> scanning bus for devices...
>>>>>> "Synchronous Abort" handler, esr 0x96000004
>>>>>> ELR:     7ff42d20
>>>>>> LR:      7ff3ff10
>>>>>> x0 : 0000000000000000 x1 : 0000000000000000
>>>>>> x2 : 0000000000000001 x3 : 000000007df1aa80
>>>>>> x4 : aaaaaaaaaaaaaaaa x5 : 0000000000000001
>>>>>> x6 : 0000000000000200 x7 : 0000000000000004
>>>>>> x8 : 000000007ff9f800 x9 : 0000000000000008
>>>>>> x10: 000000007ff9f8f0 x11: 0000000000000000
>>>>>> x12: 00000000ffffffff x13: 00000000ffffffff
>>>>>> x14: 000000007ff8242f x15: 000000007ff82435
>>>>>> x16: 000000007ff84388 x17: 000000007ff84388
>>>>>> x18: 000000007df1ade8 x19: 000000007df1aa80
>>>>>> x20: 000000007ff92cb8 x21: 000000007ff9f800
>>>>>> x22: 000000007ff9f000 x23: 0000000000000078
>>>>>> x24: 000000007ff9f8f0 x25: 0000000000000000
>>>>>> x26: 000000007ff9f800 x27: 000000007ff9f000
>>>>>> x28: 000000007ff9fb00 x29: 000000007df1aca0
>>>>>>
>>>>>> Resetting CPU ...
>>>>>>
>>>>>> resetting …
>>>>>>
>>>>>> Is this a known problem?
>>>>> Is this issue with usb?
>>>>> I have usb off on zcu102 that's why if this usb issue
>>>>> I am not aware about it.
>>>>
>>>> After a bit of digging, turns out it's CONFIG_BLK. If I disable that
>>>> things
>>>> work again (albeit without mmc access, since that one requires CONFIG_BLK
>>>> now).
>>> I don't have a zynqmp device, so cannot test with that unfortunately.
>>
>> Well, QEMU supports zcu102 emulation in the latest version, so you could use
>> that to emulate the board:
>>
>>    $ qemu-system-aarch64 -M xlnx-zcu102 -kernel u-boot.elf -nographic -m 2G
>> -drive file=u-boot,id=d,if=none -device ide-drive,drive=d,bus=ide.0
>>
>> However, I don't see the data abort with the emulated device, only with
>> actual hardware. Probably because real hardware is more upset about reading
>> from address 0 ;). But I can provoke the oops even in QEMU if I unmap the
>> first page from the memory map using the patch below.
>>
>> The oops happens in blk_dread because block_dev->bdev is NULL.
> Yes, this field really should be removed. As the comment says it's a
> hangover from pre-CONFIG_BLK where functions use a struct blk_dev * to
> specify the block device instead of a struct udevice *. It came up
> recently on a patch you sent also which is why I am so against using
> it.
>
> That said, I'm not sure why it is unset. The path should be:
>
> sdhci_bind()
> mmc_bind()
> blk_create_devicef()
> blk_create_device()
> which sets:
>
> desc->bdev = dev;
>
> [snip]

The special case about ZynqMP is that it has 2 storage backends, one 
that uses DM (the sdhc controller) and one that isn't converted to DM 
(the AHCI controller). I guess something goes wrong with the latter.


Alex