[U-Boot] [PATCH 4/4] armv7: cache: remove flush on un-aligned invalidate

Aneesh V
2011-08-11T06:29:57Z

On Wednesday 10 August 2011 11:41 PM, Anton Staaf wrote:
> On Tue, Aug 9, 2011 at 11:48 PM, Aneesh V<aneesh@ti.com> wrote:
>> Hi Anton,
>>
>> On Tuesday 09 August 2011 10:09 PM, Anton Staaf wrote:
>>>
>>> I'm not sure what the larger context of this change is, but it seems
>>> like a bad idea to me. There are a lot of locations in U-Boot that
>>
>> Please see this thread for the context.
>> http://thread.gmane.org/gmane.comp.boot-loaders.u-boot/105113/focus=105135
>
> Ahh, I missed this thread (Its title became stale). :) But I
> completely agree with the outcome, we need to fix the unaligned buffer
> problem.
>
>>
>>> will end up causing an unaligned invalidate (ext2 and dos file system
>>> code in particular). And this change will cause those unaligned
>>> invalidates to possibly throw away stores to adjacent variables. If
>>
>> No. Those partial cache-lines on the boundary are left alone. They are
>> not invalidated. So, it still affects only the party calling the
>> invalidate.
>
> Ahh, you are correct. I missed that the change would cause fewer
> cache lines to be invalidated. In this case I am much happier with
> this change. In light of this I still think the warning is a little
> mild, since it means that the driver that called the invalidate is
> certainly going to get the wrong values. Perhaps changing it to an
> error would be good (I realize that functionally it would be
> identical, but it would be more potent psychologically). I don't
> think an assert is warranted in this case since as Albert points out
> it would prevent "online" debugging of U-Boot which is a very useful
> way of working.

Ok. I will change the warning to an error.

br,
Aneesh