Re: [linux-sunxi] Re: [PATCH 10/15] drm/sun4i: tcon: Switch mux on only for composite

Maxime Ripard
2017-03-09T14:55:39Z

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On Thu, Mar 09, 2017 at 07:31:27PM +0800, Chen-Yu Tsai wrote:
> >> Additionally, the mux registers are only valid in the first TCON, meaning
> >> it must available be active in 2 pipeline chips. It's also why we'd pass
> >> "struct drm_device *" instead of "struct sun4i_tcon *".
> >
> > Hmmmm. That's going to be tricky to support. Has this been confirmed
> > somehow? Is the register used for something else on TCON1?
>
> At this point, the only reference is Allwinner's kernel, and the old 3.4
> kernel for A10/A20. I could try getting HDMI working on the A31 to get
> some real results.
>
> FWIW, the registers do not seem to be aliased across the two TCONs.

Then maybe we don't need to care, and we can just always write to the
mux?

Maxime

--
Maxime Ripard, Free Electrons
Embedded Linux and Kernel engineering
http://free-electrons.com

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