[PATCHv3] drm/sun4i: validate modes for HDMI

Maxime Ripard maxime.ripard at free-electrons.com
Fri Dec 15 21:25:31 UTC 2017


On Fri, Dec 15, 2017 at 04:21:50PM +0100, Hans Verkuil wrote:
> When I connected my cubieboard running 4.15-rc1 to my 4k display I got no picture. Some
> digging found that there is no check against the upper pixelclock limit of the HDMI
> output, so X selects a 4kp60 format at 594 MHz, which obviously won't work.
> The patch below adds a check for the upper bound of what this hardware can do, and
> it checks if the requested tmds clock can be obtained.
> It also allows for the +/- 0.5% pixel clock variation that the HDMI spec permits.
> That code is based on commit 22d0be2a557e53a22feb484e8fce255fe09e6ad5 from
> Jose Abreu for drm/arc.
> Signed-off-by: Hans Verkuil <hans.verkuil at cisco.com>
> Thanks-to: Jose Abreu <Jose.Abreu at synopsys.com>

I've fixed the checkpatch warnings, and the compilation warning about
the type mismatch (between long and unsigned long), and
applied. Thanks!


Maxime Ripard, Free Electrons
Embedded Linux and Kernel engineering

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