[U-Boot] ZynqMP breakage

[Michal Simek]

Hi,

On 6.9.2016 14:57, Simon Glass wrote:
> Hi Alex,
> 
> On 6 September 2016 at 06:55, Alexander Graf <agraf at suse.de> wrote:
>> 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.
> 
> OK, well it would be good to convert it. It certainly won't work
> without it and I'm a little surprised that it compiles :-)

probably good time to convert it. Driver itself has only sata init
sequence and then it is just compatible with ahci. That's why conversion
should be pretty easy.

Simon: Which driver should I use as inspiration for conversion?

Thanks,
Michal