[U-Boot] L2 cache and LCD on sunxi

[Simon Glass]

Hi Hans,

On 24 December 2014 at 09:47, Hans de Goede <hdegoede at redhat.com> wrote:
> Hi,
>
> On 23-12-14 05:36, Simon Glass wrote:
>>
>> Hi Hans,
>>
>> On 22 December 2014 at 09:45, Hans de Goede <hdegoede at redhat.com> wrote:
>>>
>>> Hi,
>>>
>>> On 21-12-14 19:52, Simon Glass wrote:
>>>>
>>>>
>>>> Hi,
>>>>
>>>> I ran up a banana PI and noticed that HDMI works in U-Boot. Great!
>>>>
>>>> Scrolling seems very slow though - is the L2 cache disabled perhaps?
>>>
>>>
>>>
>>> I don't think so, but it could be, I think the scrolling code is just
>>> very inefficient. Feel free to poke things a bit around this, ARM
>>> cache management is not my forte.
>>
>>
>> I think it need ssomething like the code in exynos/soc.c - see
>> v7_outer_cache_enable().
>>
>> Even with the 7 inch it's very slow.
>
>
> I've run some tests, and it is not slower then on say the A10 (cortex A8),
> also I've been unable to find any docs or allwinner code pointing to
> allwinner specific l2 cache init. As such ATM I do not believe that we've
> the l2 cache disabled.

Yes the code is not super-efficient (and could use the arch-specific
memcpy()) but I'm mostly interested in whether the platform is running
at full speed.

I'm comparing it to say an Exynos 5250 which is 1.7GHz Cortex-A15.
Without the L2 cache it scrolls quite slowly but with it it is fast.

There is probably some cache setup required.

Regards,
Simon