diff options
| author | Lyude Paul <lyude@redhat.com> | 2020-03-06 18:49:22 -0500 |
|---|---|---|
| committer | Lyude Paul <lyude@redhat.com> | 2020-03-10 14:22:42 -0400 |
| commit | 94b6ada401cbcf2e81f34ac7c5c4ca82154fd22e (patch) | |
| tree | 5b43c7014010350f17ab7b8bd903257264a2f65e /drivers/gpu/drm/drm_dp_mst_topology.c | |
| parent | 4c0a9b62b3e36bc5b06c1a796e5d4d938d9c556a (diff) | |
drm/dp_mst: Fix drm_dp_check_mstb_guid() return code
We actually expect this to return a 0 on success, or negative error code
on failure. In order to do that, we check whether or not we managed to
write the whole GUID and then return 0 if so, otherwise return a
negative error code. Also, let's add an error message here so it's a
little more obvious when this fails in the middle of a link address
probe.
This should fix issues with certain MST hubs seemingly stopping for no
reason in the middle of the link address probe process.
Fixes: cb897542c6d2 ("drm/dp_mst: Fix W=1 warnings")
Cc: Benjamin Gaignard <benjamin.gaignard@st.com>
Cc: Sean Paul <sean@poorly.run>
Cc: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Lyude Paul <lyude@redhat.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20200306234923.547873-3-lyude@redhat.com
Reviewed-by: Alex Deucher <alexander.deucher@amd.com>
Diffstat (limited to 'drivers/gpu/drm/drm_dp_mst_topology.c')
| -rw-r--r-- | drivers/gpu/drm/drm_dp_mst_topology.c | 13 |
1 files changed, 11 insertions, 2 deletions
diff --git a/drivers/gpu/drm/drm_dp_mst_topology.c b/drivers/gpu/drm/drm_dp_mst_topology.c index 6485ecaddbcb..412f8f7ecc34 100644 --- a/drivers/gpu/drm/drm_dp_mst_topology.c +++ b/drivers/gpu/drm/drm_dp_mst_topology.c @@ -2092,7 +2092,10 @@ static int drm_dp_check_mstb_guid(struct drm_dp_mst_branch *mstb, u8 *guid) } } - return ret; + if (ret < 16 && ret > 0) + return -EPROTO; + + return ret == 16 ? 0 : ret; } static void build_mst_prop_path(const struct drm_dp_mst_branch *mstb, @@ -2907,8 +2910,14 @@ static int drm_dp_send_link_address(struct drm_dp_mst_topology_mgr *mgr, drm_dp_dump_link_address(reply); ret = drm_dp_check_mstb_guid(mstb, reply->guid); - if (ret) + if (ret) { + char buf[64]; + + drm_dp_mst_rad_to_str(mstb->rad, mstb->lct, buf, sizeof(buf)); + DRM_ERROR("GUID check on %s failed: %d\n", + buf, ret); goto out; + } for (i = 0; i < reply->nports; i++) { port_mask |= BIT(reply->ports[i].port_number); |