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
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