drm/dp: Dump downstream facing port caps

It helps when the logs have a dump of the DFP capabilities.

v2: Move the dumping to the new helper

Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20200904115354.25336-2-ville.syrjala@linux.intel.com
Reviewed-by: Lyude Paul <lyude@redhat.com>
Acked-by: Daniel Vetter <daniel.vetter@ffwll.ch>

diff --git a/drivers/gpu/drm/drm_dp_helper.c b/drivers/gpu/drm/drm_dp_helper.c
index 1e7c638..c21bbfc 100644 (file)
--- a/drivers/gpu/drm/drm_dp_helper.c
+++ b/drivers/gpu/drm/drm_dp_helper.c
@@ -545,8 +545,13 @@ int drm_dp_read_downstream_info(struct drm_dp_aux *aux,
        ret = drm_dp_dpcd_read(aux, DP_DOWNSTREAM_PORT_0, downstream_ports, len);
        if (ret < 0)
                return ret;
+       if (ret != len)
+               return -EIO;
+
+       DRM_DEBUG_KMS("%s: DPCD DFP: %*ph\n",
+                     aux->name, len, downstream_ports);
 
-       return ret == len ? 0 : -EIO;
+       return 0;
 }
 EXPORT_SYMBOL(drm_dp_read_downstream_info);