[U-Boot] [RFC/PATCH] davinci: disable dcache on boards with EMAC

[Christian Riesch]

Hi Ilya,

On Mon, Nov 28, 2011 at 5:02 PM, Ilya Yanok <yanok at emcraft.com> wrote:
> Hi Christian,
>
> On 28.11.2011 19:43, Christian Riesch wrote:
>>>> What do you mean by "broken"? Is it "never working" or is it "working
>>>> sometimes" or "not working under specific conditions"? I have a DA850
>>>> based board and I use the Davinci EMAC driver (CONFIG_DRIVER_TI_EMAC).
>>>> I don't have these CONFIG_SYS_xCACHE_OFF defines in my board config
>>>> file so I guess D-Cache is enabled. But Ethernet works fine, so what
>>>> am I missing here? Is D-Cache disabled somewhere else?
>>>
>>> Today, right now?  I tried a dm365evm back in August on top-of-tree
>>> and emac didn't work until I disabled caches.  I don't have day-to-day
>>> access to that board however to confirm the current state.
>>
>> Yes, right now.
>
> I think it's because of:
>
> commit cba4b1809f043bf85c806e5a4e342f62bd5ded45
> Author: Aneesh V <aneesh at ti.com>
> Date:   Tue Aug 16 04:33:05 2011 +0000
>
>    arm: do not force d-cache enable on all boards
>
>    c2dd0d45540397704de9b13287417d21049d34c6 added dcache_enable()
>    to board_init_r(). This enables d-cache for all ARM boards.
>    As a result some of the arm boards that are not cache-ready
>    are broken. Revert this change and allow platform code to
>    take the decision on d-cache enabling.
>
>    Also add some documentation for cache usage in ARM.
>
>    Signed-off-by: Aneesh V <aneesh at ti.com>
>
> Don't you see "WARNING: Caches not enabled" message during boot?
>

Ah, yes, I see this warning, no matter whether the
CONFIG_SYS_xCACHE_OFF defines are in the config file or not.
Regards, Christian

> 2Wolfgang: So caches are actually disabled on everything except OMAP...
>
> Regards, Ilya.
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