[U-Boot] [PATCH v4 2/2] wandboard: Add support for the MX6QP variant

[Fabio Estevam]

Hi Stefano,

On Wed, Oct 4, 2017 at 9:35 AM, Fabio Estevam <festevam at gmail.com> wrote:
> Hi Stefano,
>
> On Wed, Oct 4, 2017 at 6:34 AM, Stefano Babic <sbabic at denx.de> wrote:
>
>> mmhhh...it looks to me we are diverging with this SOC. I understand that
>> current funtions are not suitable for the new SOC. However, we were able
>> to manage up now to write tables (mx6dq_iomux_ddr_regs) and use
>> functions to setup the strength and the other parameters. As your tests
>> has proofed that these functions do not work for MX6QP, the logical way
>> to do is to modify these functions instead of putting back all this code
>> in the board file. Do you agree ?
>
> Sure, I will work on using the common code for imx6qp here too.

I worked on converting this patch to using the existing DDR setup functions:
https://pastebin.com/6PGx0pMx

However I do see instability: after lauching the kernel I see a hang
after "Starting the kernel..." sometimes.

The original DDR configuration that I used from Technexion in the
original patch is very stable and never hangs.

The DDR iomux function can be used, but the mx6_dram_cfg() is the one
that gives trouble.

I understand that using the common framework is preferred, but it
seems it will require a great amount of effort to make the qp board
variant stable.

Regards,

Fabio Estevam