drm_dp_cec_register_connector() is called when registering each DP
connector in DRM, while sounds a good idea register CEC adapters as
earlier as possible, it causes some driver initialization delay
trying to do DPCD transactions in disconnected connectors.
This change will cause no regressions as drm_dp_cec_set_edid() will
still be called in further detection of connected connectors with a
valid edid parameter.
This change reduced the module load of i915 by average 0.5sec in a
machine with just one DP port disconnected while reducing more than
3sec in a machine with 4 DP ports disconnected.
Cc: Hans Verkuil <hans.verkuil@cisco.com>
Signed-off-by: José Roberto de Souza <jose.souza@intel.com>
Acked-by: Hans Verkuil <hans.verkuil@cisco.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Link: https://patchwork.freedesktop.org/patch/msgid/20181011004439.4482-1-jose.souza@intel.com
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
If aux->transfer == NULL, then just return without doing
anything. In that case the function is likely called for
a non-(e)DP connector.
This never happened for the i915 driver, but the nouveau and amdgpu
drivers need this check.
The alternative would be to add this check in those drivers before
every drm_dp_cec call, but it makes sense to check it in the
drm_dp_cec functions to prevent a kernel oops.
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/20180827075820.41109-2-hverkuil@xs4all.nl
This adds support for the DisplayPort CEC-Tunneling-over-AUX
feature that is part of the DisplayPort 1.3 standard.
Unfortunately, not all DisplayPort/USB-C to HDMI adapters with a
chip that has this capability actually hook up the CEC pin, so
even though a CEC device is created, it may not actually work.
Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com>
Reviewed-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20180711132909.25409-2-hverkuil@xs4all.nl
