From: Ville Syrjälä <ville.syrjala@linux.intel.com>
Date: Fri, 4 Sep 2020 11:53:37 +0000 (+0300)
Subject: drm/dp: Dump downstream facing port caps
X-Git-Tag: v5.10.7~1332^2~19^2~21
X-Git-Url: http://review.tizen.org/git/?a=commitdiff_plain;h=637f7240f602c078070cd2373845b7a80b59ae3f;p=platform%2Fkernel%2Flinux-rpi.git

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 1e7c638873c8..c21bbfc3d714 100644
--- 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);