From: Lyude Paul Date: Tue, 6 Nov 2018 21:30:12 +0000 (-0500) Subject: drm/i915: Fix possible race in intel_dp_add_mst_connector() X-Git-Tag: Ubuntu-4.15.0-56.62~618 X-Git-Url: https://git.proxmox.com/?a=commitdiff_plain;h=66ba4aa0c0f2815d05c51adf5bcbffe60f483fbc;p=mirror_ubuntu-bionic-kernel.git drm/i915: Fix possible race in intel_dp_add_mst_connector() BugLink: https://bugs.launchpad.net/bugs/1836802 commit 7c4512300cfa5a4dcc8c1c52ae61e3fa4bd11a39 upstream. This hasn't caused any issues yet that I'm aware of, but as Ville Syrjälä pointed out - we need to make sure that intel_connector->mst_port is set before initializing MST connectors, since in theory we could potentially check intel_connector->mst_port in i915_hpd_poll_init_work() after registering the connector but before having written it's value. Signed-off-by: Lyude Paul Reviewed-by: Ville Syrjälä Cc: Rodrigo Vivi Cc: stable@vger.kernel.org Link: https://patchwork.freedesktop.org/patch/msgid/20181106213017.14563-2-lyude@redhat.com (cherry picked from commit 66a5ab1034be801630816d1fa6cfc30db1a2f0b0) Signed-off-by: Joonas Lahtinen Signed-off-by: Greg Kroah-Hartman Signed-off-by: Kamal Mostafa Signed-off-by: Khalid Elmously --- diff --git a/drivers/gpu/drm/i915/intel_dp_mst.c b/drivers/gpu/drm/i915/intel_dp_mst.c index fd36015f8b83..37878f27191e 100644 --- a/drivers/gpu/drm/i915/intel_dp_mst.c +++ b/drivers/gpu/drm/i915/intel_dp_mst.c @@ -470,6 +470,10 @@ static struct drm_connector *intel_dp_add_mst_connector(struct drm_dp_mst_topolo if (!intel_connector) return NULL; + intel_connector->get_hw_state = intel_dp_mst_get_hw_state; + intel_connector->mst_port = intel_dp; + intel_connector->port = port; + connector = &intel_connector->base; ret = drm_connector_init(dev, connector, &intel_dp_mst_connector_funcs, DRM_MODE_CONNECTOR_DisplayPort); @@ -480,10 +484,6 @@ static struct drm_connector *intel_dp_add_mst_connector(struct drm_dp_mst_topolo drm_connector_helper_add(connector, &intel_dp_mst_connector_helper_funcs); - intel_connector->get_hw_state = intel_dp_mst_get_hw_state; - intel_connector->mst_port = intel_dp; - intel_connector->port = port; - for_each_pipe(dev_priv, pipe) { struct drm_encoder *enc = &intel_dp->mst_encoders[pipe]->base.base;