[U-Boot] [PATCH 1/2] arm: imx6: Add DDR3 calibration code for MX6 Q/D/DL

[Stefano Babic <sbabic@denx.de>]

Hi Marek,

On 24/01/2016 17:01, Marek Vasut wrote:
> On Sunday, January 24, 2016 at 11:47:56 AM, Stefano Babic wrote:
>> Hi Tim, Marek, Fabio,
>>
>> On 14/01/2016 15:25, Tim Harvey wrote:
>>> I was able to test the auto calibration a couple of weeks ago on a set
>>> of boards. I have a mix of boards with IMX6Q/IMX6DL 16/32/64bit
>>> 2/4/8Gb density - a pretty broad range. I did find the that a couple
>>> of my boards hung during mx6_dram_cfg if I skip writing anything to
>>> the calib registers (I made mx6_dram_cfg able to take a null struct
>>> mx6_mmc_calibration and call mmdc_do_write_level_calibration() and
>>> mmdc_do_dqs_calibration() automatically if null after config). I
>>> haven't had time to troubleshoot yet. Its possible I need some initial
>>> value for the calib registers or its possible there is a step in the
>>> init that should differ if we have not yet calibrated.
>>>
>>> I am all for committing what we have (as its opt-in) and we can
>>> continue to improve/test/troubleshoot.
>>
>> I was thinking about it and I agree that it is better to get it in and
>> goes on with tests, as we can achieve much more testers.
>>
>> However, I have seen that there is a general attempt for a
>> wait_for_bit() function, posted here:
>>
>> 	http://patchwork.ozlabs.org/patch/572085/
>>
>> This can help to drop the i.MX6 implementation and reuse a general utility.
> 
> This patch was not applied yet, but the conversion will be straightforward once 
> it is applied.

Yes, it is - then it is better to this before applying.

> 
> So, please apply these patches.
> 

We are not hurry for the release, and I think we have time to make
things right at once.

Best regards,
Stefano Babic

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