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authorNikola Cornij <nikola.cornij@amd.com>2021-04-30 01:11:51 +0300
committerLyude Paul <lyude@redhat.com>2021-04-30 02:11:27 +0300
commit98025a62cb00778a467dbc359d647c9515d51b4e (patch)
tree6bb916eb1540b0f4470af0221d5d22daa469d283 /drivers/gpu/drm/nouveau/dispnv50/disp.c
parent310e506c06e495b8fbe3502c70d896bc5b8b2502 (diff)
downloadlinux-98025a62cb00778a467dbc359d647c9515d51b4e.tar.xz
drm/dp_mst: Use Extended Base Receiver Capability DPCD space
[why] DP 1.4a spec mandates that if DP_EXTENDED_RECEIVER_CAP_FIELD_PRESENT is set, Extended Base Receiver Capability DPCD space must be used. Without doing that, the three DPCD values that differ will be wrong, leading to incorrect or limited functionality. MST link rate, for example, could have a lower value. Also, Synaptics quirk wouldn't work out well when Extended DPCD was not read, resulting in no DSC for such hubs. [how] Modify MST topology manager to use the values from Extended DPCD where applicable. To prevent regression on the sources that have a lower maximum link rate capability than MAX_LINK_RATE from Extended DPCD, have the drivers supply maximum lane count and rate at initialization time. This also reverts commit 2dcab875e763 ("Revert drm/dp_mst: Retrieve extended DPCD caps for topology manager"), brining the change back to the original commit ad44c03208e4 ("drm/dp_mst: Retrieve extended DPCD caps for topology manager"). Signed-off-by: Nikola Cornij <nikola.cornij@amd.com> Reviewed-by: Lyude Paul <lyude@redhat.com> Signed-off-by: Lyude Paul <lyude@redhat.com> Link: https://patchwork.freedesktop.org/patch/msgid/20210429221151.22020-2-nikola.cornij@amd.com
Diffstat (limited to 'drivers/gpu/drm/nouveau/dispnv50/disp.c')
-rw-r--r--drivers/gpu/drm/nouveau/dispnv50/disp.c3
1 files changed, 2 insertions, 1 deletions
diff --git a/drivers/gpu/drm/nouveau/dispnv50/disp.c b/drivers/gpu/drm/nouveau/dispnv50/disp.c
index 1c9c0cdf85db..c46d0374b6e6 100644
--- a/drivers/gpu/drm/nouveau/dispnv50/disp.c
+++ b/drivers/gpu/drm/nouveau/dispnv50/disp.c
@@ -1617,7 +1617,8 @@ nv50_mstm_new(struct nouveau_encoder *outp, struct drm_dp_aux *aux, int aux_max,
mstm->mgr.cbs = &nv50_mstm;
ret = drm_dp_mst_topology_mgr_init(&mstm->mgr, dev, aux, aux_max,
- max_payloads, conn_base_id);
+ (u8)max_payloads, outp->dcb->dpconf.link_nr,
+ (u8)outp->dcb->dpconf.link_bw, conn_base_id);
if (ret)
return ret;