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

[Marek Vasut]

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.

So, please apply these patches.

Best regards,
Marek Vasut