drm/amd/display: Handle branch device with DFP count = 0 case.

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[Why]
When you have a SST branch device the driver, Even no sink device connected,
it also send HPD with a valid EDID. Driver will config it to DP sink.
Therefore, there're two displays in display setting.

DPCD 0x05, DFP_PRESENT = 1 (branch device),
DFP_TYPE = 00 (Display Port)

[How]
Driver determine DPCD 0x05 DFP_PRESENT = 1(branch) as an active dongle
And check DFP count.

Signed-off-by: Hugo Hu <hugo.hu@amd.com>
Reviewed-by: Hugo Hu <Hugo.Hu@amd.com>
Acked-by: Bhawanpreet Lakha <Bhawanpreet.Lakha@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

...

This commit is contained in:

Hugo Hu 2019-02-25 19:16:52 +08:00 • committed by Alex Deucher

parent 3ae42acde3

commit a504ad265d

3 changed files with 8 additions and 8 deletions

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5

drivers/gpu/drm/amd/display/dc/core/dc_link.c

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9

drivers/gpu/drm/amd/display/dc/core/dc_link_dp.c

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2

drivers/gpu/drm/amd/display/dc/dc.h

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