drm/amd/display: pbn_div need be updated for hotplug event

link_rate sometime will be changed when DP MST connector hotplug, so
pbn_div also need be updated; otherwise, it will mismatch with
link_rate, causes no output in external monitor.

Cc: stable@vger.kernel.org
Tested-by: Daniel Wheeler <daniel.wheeler@amd.com>
Reviewed-by: Jerry Zuo <jerry.zuo@amd.com>
Acked-by: Rodrigo Siqueira <rodrigo.siqueira@amd.com>
Signed-off-by: Wade Wang <wade.wang@hp.com>
Signed-off-by: Wayne Lin <wayne.lin@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

diff --git a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c
index ddde330860fc0416b4eccac43d75425f2c3ca4b3..a144024df97c8832edda0c014f521877153ed0eb 100644 (file)
--- a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c
+++ b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c
@@ -7005,8 +7005,7 @@ static int dm_encoder_helper_atomic_check(struct drm_encoder *encoder,
        if (IS_ERR(mst_state))
                return PTR_ERR(mst_state);
 
-       if (!mst_state->pbn_div.full)
-               mst_state->pbn_div.full = dfixed_const(dm_mst_get_pbn_divider(aconnector->mst_root->dc_link));
+       mst_state->pbn_div.full = dfixed_const(dm_mst_get_pbn_divider(aconnector->mst_root->dc_link));
 
        if (!state->duplicated) {
                int max_bpc = conn_state->max_requested_bpc;