drm/i915: Skip vcpi allocation for MSTB ports that are gone

Since we need to be able to allow DPMS on->off prop changes after an MST
port has disappeared from the system, we need to be able to make sure we
can compute a config for the resulting atomic commit. Currently this is
impossible when the port has disappeared, since the VCPI slot searching
we try to do in intel_dp_mst_compute_config() will fail with -EINVAL.

Since the only commits we want to allow on no-longer-present MST ports
are ones that shut off display hardware, we already know that no VCPI
allocations are needed. So, hardcode the VCPI slot count to 0 when
intel_dp_mst_compute_config() is called on an MST port that's gone.

Changes since V4:
- Don't use mst_port_gone at all, just check whether or not the drm
  connector is registered - Daniel Vetter

Signed-off-by: Lyude Paul <[email protected]>
Reviewed-by: Daniel Vetter <[email protected]>
Cc: [email protected]
Link: https://patchwork.freedesktop.org/patch/msgid/[email protected]
(cherry picked from commit f67207d78ceaf98b7531bc22df6f21328559c8d4)
Signed-off-by: Rodrigo Vivi <[email protected]>

0 files changed, 0 insertions, 0 deletions