Commit 9bcf6d98 authored Aug 27, 2018 by Hans Verkuil

drm_dp_cec: add note about good MegaChips 2900 CEC support



A big problem with DP CEC-Tunneling-over-AUX is that it is tricky
to find adapters with a chipset that supports this AND where the
manufacturer actually connected the HDMI CEC line to the chipset.

Add a mention of the MegaChips 2900 chipset which seems to support
this feature well.

Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com>
Reviewed-by: Lyude Paul <lyude@redhat.com>
Acked-by: Alex Deucher <alexander.deucher@amd.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20180827075820.41109-3-hverkuil@xs4all.nl

parent 5ce70c79

drivers/gpu/drm/drm_dp_cec.c

+3 −1

Original line number	Diff line number	Diff line
		@@ -16,7 +16,9 @@
		* here. Quite a few active (mini-)DP-to-HDMI or USB-C-to-HDMI adapters
		* have a converter chip that supports CEC-Tunneling-over-AUX (usually the
		* Parade PS176), but they do not wire up the CEC pin, thus making CEC
		* useless.
		* useless. Note that MegaChips 2900-based adapters appear to have good
		* support for CEC tunneling. Those adapters that I have tested using
		* this chipset all have the CEC line connected.
		*
		* Sadly there is no way for this driver to know this. What happens is
		* that a /dev/cecX device is created that is isolated and unable to see

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