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

Tom Rini tom.rini at gmail.com
Mon Nov 28 15:53:25 CET 2011


On Mon, Nov 28, 2011 at 5:06 AM, Christian Riesch
<christian.riesch at omicron.at> wrote:
> Hi,
>
> On Sun, Nov 27, 2011 at 5:41 PM, Tom Rini <tom.rini at gmail.com> wrote:
>> On Sun, Nov 27, 2011 at 8:09 AM, Wolfgang Denk <wd at denx.de> wrote:
>>> In message <1321048618-20616-1-git-send-email-yanok at emcraft.com> you wrote:
>>>> DaVinci EMAC driver has no support for running with D-Cache enabled so
>>>> disable D-Cache on all DaVinci boards with EMAC device.
>>>>
>>>> Signed-off-by: Ilya Yanok <yanok at emcraft.com>
>>>> ---
>>>>
>>>> I can't test it on any DaVinci boards right now but my understanding
>>>> is that currently EMAC driver can't work properly with D-Cache enabled.
>
> [...]
>
>>> Why do we have to permanently disable the data cache just because the
>>> network driver is broken?  USB is also broken, and probably other
>>> drivers as well.
>>
>> To be clear, the problem is that today the driver is broken (not cache
>> safe) and this series of patches fixes that problem.  In doing so we
>> expose that arm926ejs doesn't have complete cache support today.
>
> 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.

-- 
Tom


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