[U-Boot] [PATCH 2/4] cache_v7: Check for dcache enablement in dcache flush functions

Aneesh V aneesh at ti.com
Wed Jun 20 18:46:33 CEST 2012


Hi Sricharan,

On 06/15/2012 07:48 AM, R, Sricharan wrote:
> Hi,
>
>>> On Fri, Jun 15, 2012 at 12:31 AM, Tom Rini<trini at ti.com>  wrote:
>>>> If we are built with D-CACHE enabled but have run 'dcache off' and then
>>>> attempt to flush unaligned regions we spam the console with problems
>>>> that aren't true (as the cache was off).
>>>>
>>>    Today we do cache maintenance operations after the dcache is turned off.
>>>    One example is before jumping to kernel, we try to invalidate the caches,
>>>    in cache turned off state. So with this patch those maintenance calls will
>>>    do nothing, which is not correct.
>>
>> Ah yes,  But, shouldn't we be doing these same operations as part of
>> turning the cache off?
>>
>    The problem is that while turning of dcaches, we flush it, and turn
>   cache and MMU off.  But these operations are not happening
>   automatically in a single call. So there is a chance of  valid
>   entries present in cache even after it is OFF.

I think this is what we need to fix. Otherwise, Tom's change looks good
to me. How about an invalidate in dcache_disable() or something like
that?

br,
Aneesh


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