[U-Boot] Very slow mtest on i.MX6UL over dual-die DDR3 (two chip selects)

[Fabio Estevam]

Hi Hector,

On Thu, May 18, 2017 at 2:06 PM, Palacios, Hector
<Hector.Palacios at digi.com> wrote:
> Hi Fabio,
>
> On Thu, 18 May 2017 17:52, Fabio Estevam wrote:
>> I got very slow performance with MX6UL when U-Boot is loaded via
>> serial download mode.
>
> That's it, actually!
> I was booting the target via USB, booting from the NAND shows normal performance.

Excellent, now we are making progress :-)

>> This gets fixed by setting the SMP bit:
>> https://patchwork.ozlabs.org/patch/747074/
>
> I don't have that patch. I guess a similar code exists somewhere that is not entered when booting from USB.

This patch has not been applied in U-Boot mainline yet. You can apply
it locally on your code for the time being.

When the board boots from SD/NAND the SMP bit is set by the ROM code
and then we do not have this problem.

When booting from serial download mode the SMP bit is not set the
system gets very slow because caches are disabled.

Regards,

Fabio Estevam