[PATCH v3 05/44] drm/nouveau/kms/nv50-: fix mst payload alloc fail crashing evo

From: Lyude Paul
Date: Tue Sep 19 2023 - 18:06:13 EST


From: Ben Skeggs <bskeggs@xxxxxxxxxx>

Programming -1 (vc_start_slot, if alloc fails) into HW probably isn't
the best idea.

Signed-off-by: Ben Skeggs <bskeggs@xxxxxxxxxx>
Reviewed-by: Lyude Paul <lyude@xxxxxxxxxx>
Acked-by: Danilo Krummrich <me@xxxxxxxx>
Signed-off-by: Lyude Paul <lyude@xxxxxxxxxx>
---
drivers/gpu/drm/nouveau/dispnv50/disp.c | 10 +++++++---
1 file changed, 7 insertions(+), 3 deletions(-)

diff --git a/drivers/gpu/drm/nouveau/dispnv50/disp.c b/drivers/gpu/drm/nouveau/dispnv50/disp.c
index 39e9ba4139c7d..889ff667d0293 100644
--- a/drivers/gpu/drm/nouveau/dispnv50/disp.c
+++ b/drivers/gpu/drm/nouveau/dispnv50/disp.c
@@ -916,23 +916,27 @@ nv50_msto_prepare(struct drm_atomic_state *state,
struct nv50_mstc *mstc = msto->mstc;
struct nv50_mstm *mstm = mstc->mstm;
struct drm_dp_mst_atomic_payload *payload;
+ int ret = 0;

NV_ATOMIC(drm, "%s: msto prepare\n", msto->encoder.name);

payload = drm_atomic_get_mst_payload_state(mst_state, mstc->port);

- // TODO: Figure out if we want to do a better job of handling VCPI allocation failures here?
if (msto->disabled) {
drm_dp_remove_payload_part1(mgr, mst_state, payload);
-
nvif_outp_dp_mst_vcpi(&mstm->outp->outp, msto->head->base.index, 0, 0, 0, 0);
+ ret = 1;
} else {
if (msto->enabled)
- drm_dp_add_payload_part1(mgr, mst_state, payload);
+ ret = drm_dp_add_payload_part1(mgr, mst_state, payload);
+ }

+ if (ret == 0) {
nvif_outp_dp_mst_vcpi(&mstm->outp->outp, msto->head->base.index,
payload->vc_start_slot, payload->time_slots,
payload->pbn, payload->time_slots * mst_state->pbn_div);
+ } else {
+ nvif_outp_dp_mst_vcpi(&mstm->outp->outp, msto->head->base.index, 0, 0, 0, 0);
}
}

--
2.41.0