[U-Boot] [PATCH RESEND v2] armv7: Disable D cache for goni target (s5p)

[Aneesh V <aneesh@ti.com>]

Hi Chander,

On Friday 29 July 2011 04:01 PM, Chander Kashyap wrote:
> Hi Aneesh,
>
> On 29 July 2011 15:43, Aneesh V<aneesh@ti.com>  wrote:
>> Hi Linus,
>>
>> On Friday 29 July 2011 04:04 AM, Linus Walleij wrote:
>>> On Thu, Jul 28, 2011 at 7:04 AM, Minkyu Kang<promsoft@gmail.com>    wrote:
>>>> Dear Linus Walleij,
>>>>
>>>> On 18 July 2011 19:35, Linus Walleij<linus.walleij@linaro.org>    wrote:
>>>>> On Mon, Jul 18, 2011 at 9:23 AM, Lukasz Majewski<l.majewski@samsung.com>    wrote:
>>>>>
>>>>>> Disable D cache for goni target (s5p) - rationale:
>>>>>>
>>>>>> 1. Before change introduced in commit
>>>>>> SHA1:c2dd0d45540397704de9b13287417d21049d34c6 the D-cache for
>>>>>> GONI target was disabled. This change was supposed to
>>>>>> preserve this state.
>>>>>
>>>>> I had exactly the same rationale for disabling cache on the Integrator - it
>>>>> used to be off now it's default on and doesn't work - but that patch was
>>>>> NAK:ed by Wolfgang.
>>>>>
>>>>
>>>> Could you please give me the link of that thread?
>>>
>>> Me:
>>> http://marc.info/?l=u-boot&m=131066804010454&w=2
>>
>> I hadn't noticed this thread before. Here are my thoughts on your
>> problem:
>>
>> I think the fundamental problem is that caching was enabled for ARM
>> without putting the cache maintenance functions in place. At a minimum,
>> we need a few flush and invalidate functions. I worked on this for
>> armv7,
> In my case i am using armv7 based board.
> Still flushing is not happening. If i am resetting the board after
> issuing saveenv command, environment is not retained.
> IMHO in armv7 still more handling need to be done. I am using mmc as boot media.

Please note that what I have provided is a means to do the flushing,
the APIs, and also I have taken care of the cleanup_beofre_linux() for
armv7. You still need to do some work to fix the issues in category (1)
below for your platform. For instance, does your MMC driver use DMA? If
yes, you may have to look into it.

best regards,
Aneesh