| Message ID | 20221104235926.302883-3-lyude@redhat.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | [1/2] drm/amdgpu/mst: Stop ignoring error codes and deadlocking | expand |
[AMD Official Use Only - General] Hi Lyude, It LGTM. Feel free to add Reviewed-by: Wayne Lin <Wayne.Lin@amd.com> > -----Original Message----- > From: Lyude Paul <lyude@redhat.com> > Sent: Saturday, November 5, 2022 7:59 AM > To: amd-gfx@lists.freedesktop.org > Cc: stable@vger.kernel.org; David Airlie <airlied@gmail.com>; Daniel Vetter > <daniel@ffwll.ch>; Jani Nikula <jani.nikula@intel.com>; Thomas > Zimmermann <tzimmermann@suse.de>; Lin, Wayne > <Wayne.Lin@amd.com>; Imre Deak <imre.deak@intel.com>; Mikita Lipski > <mikita.lipski@amd.com>; Deucher, Alexander > <Alexander.Deucher@amd.com>; open list:DRM DRIVERS <dri- > devel@lists.freedesktop.org>; open list <linux-kernel@vger.kernel.org> > Subject: [PATCH 2/2] drm/display/dp_mst: Fix > drm_dp_mst_add_affected_dsc_crtcs() return code > > Looks like that we're accidentally dropping a pretty important return code > here. For some reason, we just return -EINVAL if we fail to get the MST > topology state. This is wrong: error codes are important and should never be > squashed without being handled, which here seems to have the potential to > cause a deadlock. > > Signed-off-by: Lyude Paul <lyude@redhat.com> > Fixes: 8ec046716ca8 ("drm/dp_mst: Add helper to trigger modeset on > affected DSC MST CRTCs") > Cc: <stable@vger.kernel.org> # v5.6+ > --- > drivers/gpu/drm/display/drm_dp_mst_topology.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/drivers/gpu/drm/display/drm_dp_mst_topology.c > b/drivers/gpu/drm/display/drm_dp_mst_topology.c > index ecd22c038c8c0..51a46689cda70 100644 > --- a/drivers/gpu/drm/display/drm_dp_mst_topology.c > +++ b/drivers/gpu/drm/display/drm_dp_mst_topology.c > @@ -5186,7 +5186,7 @@ int drm_dp_mst_add_affected_dsc_crtcs(struct > drm_atomic_state *state, struct drm > mst_state = drm_atomic_get_mst_topology_state(state, mgr); > > if (IS_ERR(mst_state)) > - return -EINVAL; > + return PTR_ERR(mst_state); > > list_for_each_entry(pos, &mst_state->payloads, next) { > > -- > 2.37.3
diff --git a/drivers/gpu/drm/display/drm_dp_mst_topology.c b/drivers/gpu/drm/display/drm_dp_mst_topology.c index ecd22c038c8c0..51a46689cda70 100644 --- a/drivers/gpu/drm/display/drm_dp_mst_topology.c +++ b/drivers/gpu/drm/display/drm_dp_mst_topology.c @@ -5186,7 +5186,7 @@ int drm_dp_mst_add_affected_dsc_crtcs(struct drm_atomic_state *state, struct drm mst_state = drm_atomic_get_mst_topology_state(state, mgr); if (IS_ERR(mst_state)) - return -EINVAL; + return PTR_ERR(mst_state); list_for_each_entry(pos, &mst_state->payloads, next) {
Looks like that we're accidentally dropping a pretty important return code here. For some reason, we just return -EINVAL if we fail to get the MST topology state. This is wrong: error codes are important and should never be squashed without being handled, which here seems to have the potential to cause a deadlock. Signed-off-by: Lyude Paul <lyude@redhat.com> Fixes: 8ec046716ca8 ("drm/dp_mst: Add helper to trigger modeset on affected DSC MST CRTCs") Cc: <stable@vger.kernel.org> # v5.6+ --- drivers/gpu/drm/display/drm_dp_mst_topology.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)