[PATCH v5 05/20] drm/nouveau/kms: Don't clear DP_MST_CTRL DPCD in nv50_mstm_new()

Lyude Paul
2020-08-26T18:25:34Z

Since fa3cdf8d0b09 ("drm/nouveau: Reset MST branching unit before
enabling") we've been clearing DP_MST_CTRL before we start enabling MST.
Since then clearing DP_MST_CTRL in nv50_mstm_new() has been unnecessary
and redundant, so let's remove it.

Signed-off-by: Lyude Paul <lyude@redhat.com>
Reviewed-by: Ben Skeggs <bskeggs@redhat.com>
---
drivers/gpu/drm/nouveau/dispnv50/disp.c | 11 -----------
1 file changed, 11 deletions(-)

diff --git a/drivers/gpu/drm/nouveau/dispnv50/disp.c b/drivers/gpu/drm/nouveau/dispnv50/disp.c
index e7874877da858..c4d138f0ca054 100644
--- a/drivers/gpu/drm/nouveau/dispnv50/disp.c
+++ b/drivers/gpu/drm/nouveau/dispnv50/disp.c
@@ -1535,17 +1535,6 @@ nv50_mstm_new(struct nouveau_encoder *outp, struct drm_dp_aux *aux, int aux_max,
struct drm_device *dev = outp->base.base.dev;
struct nv50_mstm *mstm;
int ret;
- u8 dpcd;
-
- /* This is a workaround for some monitors not functioning
- * correctly in MST mode on initial module load. I think
- * some bad interaction with the VBIOS may be responsible.
- *
- * A good ol' off and on again seems to work here ;)
- */
- ret = drm_dp_dpcd_readb(aux, DP_DPCD_REV, &dpcd);
- if (ret >= 0 && dpcd >= 0x12)
- drm_dp_dpcd_writeb(aux, DP_MSTM_CTRL, 0);

if (!(mstm = *pmstm = kzalloc(sizeof(*mstm), GFP_KERNEL)))
return -ENOMEM;
--
2.26.2