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

Aneesh V
2012-06-20T16:46:33Z

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@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