From 10cfc2e176245948b2af276bac64b400c4d5a6da Mon Sep 17 00:00:00 2001 From: Stanislav Lisovskiy Date: Tue, 1 Nov 2022 11:42:18 +0200 Subject: [PATCH] drm/i915: Fix intel_dp_mst_compute_link_config We currently always exit that bpp loop because drm_dp_atomic_find_vcpi_slots doesn't care if we actually can fit those or not. I think that wasn't the initial intention here, especially when we keep trying with lower bpps, we are supposed to keep trying until we actually find some _working_ configuration, which isn't the case here. So added that drm_dp_mst_check here, so that we can make sure that try all the bpps before we fail. Reviewed-by: Vinod Govindapillai Signed-off-by: Stanislav Lisovskiy Link: https://patchwork.freedesktop.org/patch/msgid/20221101094222.22091-3-stanislav.lisovskiy@intel.com --- drivers/gpu/drm/i915/display/intel_dp_mst.c | 16 ++++++++++++++-- 1 file changed, 14 insertions(+), 2 deletions(-) diff --git a/drivers/gpu/drm/i915/display/intel_dp_mst.c b/drivers/gpu/drm/i915/display/intel_dp_mst.c index 4077a979a924..823dfceefd90 100644 --- a/drivers/gpu/drm/i915/display/intel_dp_mst.c +++ b/drivers/gpu/drm/i915/display/intel_dp_mst.c @@ -60,6 +60,7 @@ static int intel_dp_mst_compute_link_config(struct intel_encoder *encoder, const struct drm_display_mode *adjusted_mode = &crtc_state->hw.adjusted_mode; int bpp, slots = -EINVAL; + int ret = 0; mst_state = drm_atomic_get_mst_topology_state(state, &intel_dp->mst_mgr); if (IS_ERR(mst_state)) @@ -85,10 +86,21 @@ static int intel_dp_mst_compute_link_config(struct intel_encoder *encoder, connector->port, crtc_state->pbn); if (slots == -EDEADLK) return slots; - if (slots >= 0) - break; + if (slots >= 0) { + ret = drm_dp_mst_atomic_check(state); + /* + * If we got slots >= 0 and we can fit those based on check + * then we can exit the loop. Otherwise keep trying. + */ + if (!ret) + break; + } } + /* Despite slots are non-zero, we still failed the atomic check */ + if (ret && slots >= 0) + slots = ret; + if (slots < 0) { drm_dbg_kms(&i915->drm, "failed finding vcpi slots:%d\n", slots);