Messages in this thread | | | From | Vasily Khoruzhick <> | Date | Sat, 2 Feb 2019 17:32:42 -0800 | Subject | Re: [PATCH 9/9] [DO NOT MERGE] drm/sun4i: rgb: Add 5% tolerance to dot clock frequency check |
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On Thu, Oct 18, 2018 at 4:31 AM Laurent Pinchart <laurent.pinchart@ideasonboard.com> wrote:
> Given that the tolerance is a property of the panel or bridge, I agree with > Daniel that it should be implemented there, or at least in cooperation with > drm_panel and drm_bridge.
Clock tolerance is not specified in ANX6345 datasheet.
> Semi-related information, I think the CEA and VESA standards allow a 0.5% > clock tolerance. What is the maximum clock frequency deviation required for > this platform ?
This particular platform requires ~1% deviation.
E.g. on Pinebook with 768p panel: requested clock: 73.0 MHz, real clock: 72.296296 MHz (0.96%) on Pinebook with 1080p panel: requested clock: 138.5 MHz, real clock: 138.461538 MHz (0.03%)
So unfortunately 0.5% is not enough.
Regards, Vasily
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