[U-Boot] SPL variant of sunxi nand module

[Nikolai Zhubr <n-a-zhubr@yandex.ru>]

Hi again,

The following commit (titled "use PIO instead of DMA") apparently broke 
actual reading of nand pages in SPL at least for A20:

http://git.denx.de/?p=u-boot.git;a=commit;h=6ddbb1e936c78cdef1e7395039fa7020c5c75326

Instead of reading page contents, non-dma (current) version just feeds 
zeroes here.
Tested on A20-olinuxino-micro with a Hynix 4GB nand chip.

It'd be nice to somehow fix it back eventually :)

Other than that, nand boot seems usable (with added necessary chip id).


Thank you,

Regards,
Nikolai

24.12.2018 0:00, I wrote:
> 23.12.2018 21:58, I wrote:
> [...]
>> Regarding the sunxi_nand_spl.c module, I can not find any mention if it
>> implies NAND_ECC_HW, NAND_ECC_HW_SYNDROME, or rather some other mode, or
>> if these modes are irrelevant in this case?
>
> So far I'm observing that sunxi_nand_spl module refuses to load erased
> nand pages (500000 in the example below), which is correct, but it
> "successfully" loads filled nand pages as totally zeroed out, which is
> supposedly incorrect. This is in contrast with sunxi_nand module, that
> loads filled pages correctly, at least in my simple tests.
>
> So while detection in sunxi_nand_spl seems fine, reading seems not.
>
> I think digging deeper without some additional advice is a bit beyond my
> capabilities, although most probably some very tiny bits are missing...
>
>
> Thank you,
>
> Regards,
> Nikolai
>
> U-Boot SPL 2019.01-rc2 (Dec 23 2018 - 23:23:57 +0300)
> CPU: 912000000Hz, AXI/AHB/APB: 3/2/2
> DRAM: 1024 MiB
>  >>SPL: board_init_r()
> Trying to boot from NAND
> spl: nand - using hw ecc
> [zh]nand_spl_load_image(500000, 40)=-22
> [zh]Read dump of page 768 (nand offs 600000, page_size 8192):
> 0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,
> [zh]Read dump of page 768 (nand offs 600000, page_size 8192):
> 0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,
> =====================================================
> U-Boot 2019.01-rc2 (Dec 23 2018 - 22:30:35 +0300) Allwinner Technology
>
> CPU: Allwinner A20 (SUN7I)
> Model: Olimex A20-Olinuxino Micro
> I2C: ready
> DRAM: 1 GiB
> NAND: nand_base: device found, Manufacturer ID: 0xad, Chip ID: 0xd7
> nand_base: Hynix H27UBG8T2BTR-BC 32G 3.3V 8-bit
> nand_base: Hynix H27UBG8T2BTR-BC 32G 3.3V 8-bit
> nand_base: 4096 MiB, MLC, erase size: 2048 KiB, page size: 8192, OOB
> size: 640
> Using ECC step 1024, strength 40, mode 2
> 4096 MiB
> In: serial
> Out: serial
> Err: serial
> SCSI: SATA link 0 timeout.
> AHCI 0001.0100 32 slots 1 ports 3 Gbps 0x1 impl SATA mode
> flags: ncq stag pm led clo only pmp pio slum part ccc apst
>
> Net: Can't get reset: -524
> eth0: ethernet at 1c50000
> Hit any key to stop autoboot: 0
> => nand read 0x45000000 0x400000 0x1000
>
> NAND read: device 0 offset 0x400000, size 0x1000
> Scanning device for bad blocks
> Bad eraseblock 0 at 0x0000001fe000
> Bad eraseblock 1 at 0x0000003fe000
> 4096 bytes read: OK
> => md.b 0x45000000 100
> 45000000: b8 00 00 ea 14 f0 9f e5 14 f0 9f e5 14 f0 9f e5 ................
> =====================================================
>
>
>>
>> Can not guess browsing through the code, it looks too different from
>> sunxi_nand.c to compare.
>>
>>
>> Thank you,
>>
>> Regards,
>> Nikolai
>>
>>
>>> On the other hand, normal U-boot variant reads correct data from nand,
>>> but I'm not yet sure if it uses correct parameters and specifically, if
>>> they match those of SPL version. Need to add yet more debugging output.
>>>
>>>
>>> Thank you,
>>>
>>> Regards,
>>> Nikolai
>>>
>>>> Michael
>>>>
>>>>>
>>>>> Now the detection routine in sunxi_nand_spl apparently comes up with a
>>>>> value of ecc_strength=4 instead... Why is that?
>>>>
>>>> n - 1 using an index, if the code that I have is aligned so
>>>>
>>>> Michael
>>>>
>>>>>
>>>>>
>>>>> Thank you,
>>>>>
>>>>> Regards,
>>>>> Nikolai
>>>>>
>>>>>
>>>>>>
>>>>>>
>>>>>> Thank you,
>>>>>>
>>>>>> Regards,
>>>>>> Nikolai
>>>>>> _______________________________________________
>>>>>> U-Boot mailing list
>>>>>> U-Boot at lists.denx.de
>>>>>> https://lists.denx.de/listinfo/u-boot
>>>>>
>>>>> _______________________________________________
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>>>>
>>>>
>>>>
>>>
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>