linux-kernel - RE: fsl-dcu not works on latest "drm-next"

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Date:	Wed, 25 May 2016 09:59:39 +0000
From:	Meng Yi <meng.yi@....com>
To:	Mark Brown <broonie@...nel.org>
CC:	"dri-devel@...ts.freedesktop.org" <dri-devel@...ts.freedesktop.org>,
	"David Airlie" <airlied@...ux.ie>, Stefan Agner <stefan@...er.ch>,
	"airlied@...hat.com" <airlied@...hat.com>,
	"linux-kernel@...r.kernel.org" <linux-kernel@...r.kernel.org>
Subject: RE: fsl-dcu not works on latest "drm-next"

Hi Mark,

> 
> Without any description of the problem it is difficult to comment.
> There were some drivers that were abusing the API by hacking round things
> that need fixing (the main one I've seen is reporting things as big endian
> instead of native endian to cause two layers of translation to kick in) and one
> that was trying to use regmap to represent something that just fundamentally
> wasn't a regmap so *any* change in regmap internals was risky.

I was testing HDMI patches on latest "drm-next" branch, and found that it is not work.
And then I found the base tree was not working too. Then I debugged the base tree.

I read out the value of relevant register using "CodeWarrior TAP", find that endianness is not right.

Then I changed endianness of the value to be written that using " regmap_write" . It works.
But "regmap_update_bits" still have the problem.

I had checked log of regmap, and didn't find which commit caused that.

I am not familiar with regmap, can you give some advices?

Thanks,
Best Regards,
Meng Yi