From 5e292e7646ef369e6f19c1f83f7795d5eafe3455 Mon Sep 17 00:00:00 2001 From: Lyude Paul Date: Thu, 10 Jan 2019 19:53:36 -0500 Subject: [PATCH] drm/nouveau: Remove unnecessary VCPI checks in nv50_msto_cleanup() There is no need to look at the port's VCPI allocation before calling drm_dp_mst_deallocate_vcpi(), as we already have msto->disabled to let us avoid cleaning up an msto more then once. The DP MST core will never call drm_dp_mst_deallocate_vcpi() on it's own, which is presumably what these checks are meant to protect against. More importantly though, we're about to stop clearing mstc->port in the next commit, which means if we could potentially hit a use-after-free error if we tried to check mstc->port->vcpi here. So to make life easier for anyone who bisects this code in the future, use msto->disabled instead to check whether or not we need to deallocate VCPI instead. Signed-off-by: Lyude Paul Reviewed-by: Ben Skeggs Cc: Daniel Vetter Cc: David Airlie Cc: Jerry Zuo Cc: Harry Wentland Cc: Juston Li Link: https://patchwork.freedesktop.org/patch/msgid/20190111005343.17443-14-lyude@redhat.com --- drivers/gpu/drm/nouveau/dispnv50/disp.c | 15 +++++++++------ 1 file changed, 9 insertions(+), 6 deletions(-) diff --git a/drivers/gpu/drm/nouveau/dispnv50/disp.c b/drivers/gpu/drm/nouveau/dispnv50/disp.c index d173cdd6ee3f..a043fafd8eaa 100644 --- a/drivers/gpu/drm/nouveau/dispnv50/disp.c +++ b/drivers/gpu/drm/nouveau/dispnv50/disp.c @@ -696,14 +696,17 @@ nv50_msto_cleanup(struct nv50_msto *msto) struct nv50_mstc *mstc = msto->mstc; struct nv50_mstm *mstm = mstc->mstm; + if (!msto->disabled) + return; + NV_ATOMIC(drm, "%s: msto cleanup\n", msto->encoder.name); - if (mstc->port && mstc->port->vcpi.vcpi > 0 && !nv50_msto_payload(msto)) + + if (mstc->port) drm_dp_mst_deallocate_vcpi(&mstm->mgr, mstc->port); - if (msto->disabled) { - msto->mstc = NULL; - msto->head = NULL; - msto->disabled = false; - } + + msto->mstc = NULL; + msto->head = NULL; + msto->disabled = false; } static void -- 2.30.2