Re: [PATCH v2 06/13] drm/sun4i: hdmi: Allow using second PLL as TMDS clk parent

[Maxime Ripard]

On Tue, Sep 26, 2017 at 06:59:12AM +0000, Chen-Yu Tsai wrote:
> Allwinner SoCs typically have two PLLs reserved for video related usage.
> At the moment we only support using the first one to feed the HDMI
> transmitter block's TMDS clock.
> 
> Let the HDMI encoder's TMDS clock go through all of its parents when
> calculating possible clock rates. This allows usage of the second video
> PLL as its parent.
> 
> Note that this does not handle conflicting pixel clocks. It is entirely
> possible to have an LCD panel use one pixel clock rate, only to be
> overridden by the HDMI transmitter's clock rate request when the second
> display pipeline is enabled.
> 
> This should be handled by having all the clock drivers honor clock rate
> ranges, and have the consumers use clk_set_rate_min/clk_set_rate_max.

That, or relying on clk_set_rate_protect

Acked-by: Maxime Ripard <maxime.ripard@xxxxxxxxxxxxxxxxxx>

Maxime

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

Attachment: signature.asc
Description: PGP signature