From: Hans Verkuil Date: Mon, 27 Aug 2018 07:58:17 +0000 (+0200) Subject: drm_dp_cec: add note about good MegaChips 2900 CEC support X-Git-Url: http://git.lede-project.org./?a=commitdiff_plain;h=9bcf6d9868ae95fc7e5eda3dae5200f234ea5623;p=openwrt%2Fstaging%2Fblogic.git 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 Reviewed-by: Lyude Paul Acked-by: Alex Deucher Link: https://patchwork.freedesktop.org/patch/msgid/20180827075820.41109-3-hverkuil@xs4all.nl --- diff --git a/drivers/gpu/drm/drm_dp_cec.c b/drivers/gpu/drm/drm_dp_cec.c index 1407b13a8d5d..8a718f85079a 100644 --- a/drivers/gpu/drm/drm_dp_cec.c +++ b/drivers/gpu/drm/drm_dp_cec.c @@ -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