On Wed, Apr 18, 2012 at 01:43:46PM +0530, Archit Taneja wrote:
> 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.

I was just going to ask about this, as I haven't noticed any improvement
in mainline kernels since I reported the original failure...
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