drm/amd/display: Passive DP->HDMI dongle detection fix
authorMichael Strauss <michael.strauss@amd.com>
Thu, 3 Oct 2019 15:54:15 +0000 (11:54 -0400)
committerAlex Deucher <alexander.deucher@amd.com>
Fri, 25 Oct 2019 20:50:09 +0000 (16:50 -0400)
commit71fb7b2801a7fcea919c1e1da7fe2bf19b165f04
tree4133e147d90ffde1217fdcca2edeb3cf57a1807e
parentbf7f5ac3167a75f60c2f27f16613a6ab90e55908
drm/amd/display: Passive DP->HDMI dongle detection fix

[WHY]
i2c_read is called to differentiate passive DP->HDMI and DP->DVI-D dongles
The call is expected to fail in DVI-D case but pass in HDMI case
Some HDMI dongles have a chance to fail as well, causing misdetection as DVI-D

[HOW]
Retry i2c_read to ensure failed result is valid

Signed-off-by: Michael Strauss <michael.strauss@amd.com>
Reviewed-by: Tony Cheng <Tony.Cheng@amd.com>
Acked-by: Leo Li <sunpeng.li@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
drivers/gpu/drm/amd/display/dc/core/dc_link_ddc.c