drm/nouveau/disp/dp: maintain link in response to hpd signal
This previously worked for the most part due to userspace doing a
modeset in response to HPD interrupts. This will allow us to
properly handle cases where sync is lost for other reasons, or if
userspace isn't caring.
Signed-off-by: Ben Skeggs <bskeggs@redhat.com>
diff --git a/drivers/gpu/drm/nouveau/core/engine/disp/nvd0.c b/drivers/gpu/drm/nouveau/core/engine/disp/nvd0.c
index 77e7ade..4eb16e9 100644
--- a/drivers/gpu/drm/nouveau/core/engine/disp/nvd0.c
+++ b/drivers/gpu/drm/nouveau/core/engine/disp/nvd0.c
@@ -1138,6 +1138,7 @@
if (!outp)
return;
+ /* see note in nv50_disp_intr_unk20_2() */
if (outp->info.type == DCB_OUTPUT_DP) {
u32 sync = nv_rd32(priv, 0x660404 + (head * 0x300));
switch ((sync & 0x000003c0) >> 6) {
@@ -1149,7 +1150,8 @@
break;
}
- nouveau_dp_train((void *)outp, pclk);
+ if (nvkm_output_dp_train(outp, pclk, true))
+ ERR("link not trained before attach\n");
}
exec_clkcmp(priv, head, 0, pclk, &conf);