[PATCH 02/16] drm/amd/display: Check status from dpcd_get_tunneling_device_data

[Roman.Li at amd.com]

From: Alex Hung <alex.hung at amd.com>

[WHAT & HOW]
dpcd_get_tunneling_device_data calls core_link_read_dpcd which can
fail. The status from core_link_read_dpcd should be checked and error
messages is printed in case of failures.

This fixes 1 UNUSED_VALUE issue reported by Coverity.

Reviewed-by: Rodrigo Siqueira <rodrigo.siqueira at amd.com>
Signed-off-by: Alex Hung <alex.hung at amd.com>
Signed-off-by: Roman Li <roman.li at amd.com>
---
 .../drm/amd/display/dc/link/protocols/link_dp_capability.c | 2 ++
 .../gpu/drm/amd/display/dc/link/protocols/link_dp_dpia.c   | 7 +++++++
 2 files changed, 9 insertions(+)

diff --git a/drivers/gpu/drm/amd/display/dc/link/protocols/link_dp_capability.c b/drivers/gpu/drm/amd/display/dc/link/protocols/link_dp_capability.c
index 286841456157..2ec968f239f7 100644
--- a/drivers/gpu/drm/amd/display/dc/link/protocols/link_dp_capability.c
+++ b/drivers/gpu/drm/amd/display/dc/link/protocols/link_dp_capability.c
@@ -1636,6 +1636,8 @@ static bool retrieve_link_cap(struct dc_link *link)
 
 	/* Read DP tunneling information. */
 	status = dpcd_get_tunneling_device_data(link);
+	if (status != DC_OK)
+		dm_error("%s: Read tunndeling device data failed.\n", __func__);
 
 	dpcd_set_source_specific_data(link);
 	/* Sink may need to configure internals based on vendor, so allow some
diff --git a/drivers/gpu/drm/amd/display/dc/link/protocols/link_dp_dpia.c b/drivers/gpu/drm/amd/display/dc/link/protocols/link_dp_dpia.c
index 6af42ba9885c..0d123e647652 100644
--- a/drivers/gpu/drm/amd/display/dc/link/protocols/link_dp_dpia.c
+++ b/drivers/gpu/drm/amd/display/dc/link/protocols/link_dp_dpia.c
@@ -59,12 +59,18 @@ enum dc_status dpcd_get_tunneling_device_data(struct dc_link *link)
 			dpcd_dp_tun_data,
 			sizeof(dpcd_dp_tun_data));
 
+	if (status != DC_OK)
+		goto err;
+
 	status = core_link_read_dpcd(
 			link,
 			DP_USB4_ROUTER_TOPOLOGY_ID,
 			dpcd_topology_data,
 			sizeof(dpcd_topology_data));
 
+	if (status != DC_OK)
+		goto err;
+
 	link->dpcd_caps.usb4_dp_tun_info.dp_tun_cap.raw =
 			dpcd_dp_tun_data[DP_TUNNELING_CAPABILITIES_SUPPORT - DP_TUNNELING_CAPABILITIES_SUPPORT];
 	link->dpcd_caps.usb4_dp_tun_info.dpia_info.raw =
@@ -75,6 +81,7 @@ enum dc_status dpcd_get_tunneling_device_data(struct dc_link *link)
 	for (i = 0; i < DPCD_USB4_TOPOLOGY_ID_LEN; i++)
 		link->dpcd_caps.usb4_dp_tun_info.usb4_topology_id[i] = dpcd_topology_data[i];
 
+err:
 	return status;
 }
 
-- 
2.34.1