Re: [PATCH] ARM: OMAP: Revert "ARM: OMAP: ctrl: Fix CONTROL_DSIPHY register fields"

[Archit Taneja <a0393947@ti.com>]

On Wednesday 18 April 2012 01:36 PM, Tomi Valkeinen wrote:
> Hi,
>
> On Mon, 2012-04-09 at 12:41 +0530, Archit Taneja wrote:
>> This reverts commit 46f8c3c7e95c0d30d95911e7975ddc4f93b3e237.
>>
>> The commit above swapped the DSI1_PPID and DSI2_PPID register fields in
>> CONTROL_DSIPHY to be in sync with the newer public OMAP TRMs(after version V).
>>
>> With this commit, contention errors were reported on DSI lanes some OMAP4 SDPs.
>> After probing the DSI lanes on OMAP4 SDP, it was seen that setting bits in the
>> DSI2_PPID field was pulling up voltage on DSI1 lanes, and DSI1_PPID field was
>> pulling up voltage on DSI2 lanes.
>>
>> This proves that the current version of OMAP4 TRM is incorrect, swap the
>> position of register fields according to the older TRM versions as they were
>> correct.
>
> Are we sure the bits are the same for all OMAP4 versions? I'm just
> wondering why the change was made to TRM...

I've tried on OMAP4430 ES2.1 and OMAP4460 ES1.1. I can try on a couple 
more revisions.

As far as why the change was made in the TRM, it's a bit hard to find 
the right people, or get response from them :), I'll give that a try again.

If we do conclude that this revert patch is needed, it might probably be 
a candidate for the 3.2 and 3.3 stable kernels, just wanted to point 
that out.

Archit

>
>   Tomi
>