[U-Boot] sunxi: reduce Orange Pi Zero DRAM clock speed

Using `fel-boot-lima-memtester-on-orange-pi-pc 672` on an Orange Pi
without heatsink results in the following error after a few minutes:
  WRITE FAILURE: 0x00200000 != 0xffdfffff at offset 0x0137f47c (bitflip).

Also, the constructor repository (github/orangepi-xunlong) seems to
contain that 624 Mhz clock speed in its u-boot fork. It may be that 672
Mhz is the advertized overclocked speed.

According to http://linux-sunxi.org/Orange_Pi_PC#DRAM_clock_speed_limit
it may be worth decreasing that value with other Orange Pi boards.

See also e7d6aa0b74b7f4d08ee68da8a586c76c761348e2.
---
 configs/orangepi_zero_defconfig | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

On Mon, Jul 24, 2017 at 1:44 AM, Clément Bœsch <u@pkh.me> wrote:
> Using `fel-boot-lima-memtester-on-orange-pi-pc 672` on an Orange Pi
> without heatsink results in the following error after a few minutes:
>   WRITE FAILURE: 0x00200000 != 0xffdfffff at offset 0x0137f47c (bitflip).
>
> Also, the constructor repository (github/orangepi-xunlong) seems to
> contain that 624 Mhz clock speed in its u-boot fork. It may be that 672
> Mhz is the advertized overclocked speed.
>
> According to http://linux-sunxi.org/Orange_Pi_PC#DRAM_clock_speed_limit
> it may be worth decreasing that value with other Orange Pi boards.
>
> See also e7d6aa0b74b7f4d08ee68da8a586c76c761348e2.

Applied to u-boot-sunxi/master

thanks!

On 2017-08-11 12:21, Jagan Teki wrote:
> On Mon, Jul 24, 2017 at 1:44 AM, Clément Bœsch <u@pkh.me> wrote:
>> Using `fel-boot-lima-memtester-on-orange-pi-pc 672` on an Orange Pi
>> without heatsink results in the following error after a few minutes:
>>   WRITE FAILURE: 0x00200000 != 0xffdfffff at offset 0x0137f47c (bitflip).
>>
>> Also, the constructor repository (github/orangepi-xunlong) seems to
>> contain that 624 Mhz clock speed in its u-boot fork. It may be that 672
>> Mhz is the advertized overclocked speed.
>>
>> According to http://linux-sunxi.org/Orange_Pi_PC#DRAM_clock_speed_limit
>> it may be worth decreasing that value with other Orange Pi boards.
>>
>> See also e7d6aa0b74b7f4d08ee68da8a586c76c761348e2.
> 
> Applied to u-boot-sunxi/master
> 

I've a 1.5 years old OPi Zero that was running uboot 2017.01 so far. I
just tried to update to 2018.05, also using the new defconfig. The
result was that uboot got stuck early during the first lines of output.
Then I changed the DRAM clock back to 672, and things seem to work find.

Are we facing different board revisions that need different settings, or
could the lowering be incorrect?

Jan

On 2018-05-31 19:36, Jan Kiszka wrote:
> On 2017-08-11 12:21, Jagan Teki wrote:
>> On Mon, Jul 24, 2017 at 1:44 AM, Clément Bœsch <u@pkh.me> wrote:
>>> Using `fel-boot-lima-memtester-on-orange-pi-pc 672` on an Orange Pi
>>> without heatsink results in the following error after a few minutes:
>>>   WRITE FAILURE: 0x00200000 != 0xffdfffff at offset 0x0137f47c (bitflip).
>>>
>>> Also, the constructor repository (github/orangepi-xunlong) seems to
>>> contain that 624 Mhz clock speed in its u-boot fork. It may be that 672
>>> Mhz is the advertized overclocked speed.
>>>
>>> According to http://linux-sunxi.org/Orange_Pi_PC#DRAM_clock_speed_limit
>>> it may be worth decreasing that value with other Orange Pi boards.
>>>
>>> See also e7d6aa0b74b7f4d08ee68da8a586c76c761348e2.
>>
>> Applied to u-boot-sunxi/master
>>
> 
> I've a 1.5 years old OPi Zero that was running uboot 2017.01 so far. I
> just tried to update to 2018.05, also using the new defconfig. The
> result was that uboot got stuck early during the first lines of output.
> Then I changed the DRAM clock back to 672, and things seem to work find.
> 
> Are we facing different board revisions that need different settings, or
> could the lowering be incorrect?

Sorry, false alarm. Seems I messed up something when writing out the 624
MHz version and happen to fix that while testing the 672 one. But now
also the upstream config works. And I suspect/hope that the lower
frequency will resolve the sporadic crashes of the board that I saw in
the past...

Thanks,
Jan