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

Tom Rini
2012-06-15T14:07:58Z

On 06/14/2012 10:48 PM, R, Sricharan wrote:
> Hi Tom,
>
> 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?

> If it is a problem with unaligned regions, then that is the only
> thing to be fixed
> right ?. Just trying to understand why this change is required ?

The problem is that within the USB/network/filesystem stacks we have a
lot of not cache safe alignments apparently. Without this every '#' of
a tftp gives a screen full of error printfs. So tftp'ing a kernel takes
minutes, not seconds, to complete.

--
Tom