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
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
