drm/amd/display: Fix uninitialized variable.

[Why]
Uninitialized variable causes diag compilation build failure.

[How]
- Ensure that variable in question is always initialized before being
used.
- The variable in question is the USB4 DP training pattern. In case an
unsupported training pattern has been requested, update status
accordingly and abort current link training attempt.

Reviewed-by: Meenakshikumar Somasundaram <Meenakshikumar.Somasundaram@amd.com>
Acked-by: Alan Liu <HaoPing.Liu@amd.com>
Signed-off-by: Jimmy Kizito <Jimmy.Kizito@amd.com>
Tested-by: Daniel Wheeler <daniel.wheeler@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

diff --git a/drivers/gpu/drm/amd/display/dc/core/dc_link_dpia.c b/drivers/gpu/drm/amd/display/dc/core/dc_link_dpia.c
index c8610a5..3b8acda 100644 (file)
--- a/drivers/gpu/drm/amd/display/dc/core/dc_link_dpia.c
+++ b/drivers/gpu/drm/amd/display/dc/core/dc_link_dpia.c
@@ -202,30 +202,34 @@ static uint8_t dpia_build_set_config_data(enum dpia_set_config_type type,
 }
 
 /* Convert DC training pattern to DPIA training stage. */
-static enum dpia_set_config_ts convert_trng_ptn_to_trng_stg(enum dc_dp_training_pattern tps)
+static enum dc_status convert_trng_ptn_to_trng_stg(enum dc_dp_training_pattern tps, enum dpia_set_config_ts *ts)
 {
-       enum dpia_set_config_ts ts;
+       enum dc_status status = DC_OK;
 
        switch (tps) {
        case DP_TRAINING_PATTERN_SEQUENCE_1:
-               ts = DPIA_TS_TPS1;
+               *ts = DPIA_TS_TPS1;
                break;
        case DP_TRAINING_PATTERN_SEQUENCE_2:
-               ts = DPIA_TS_TPS2;
+               *ts = DPIA_TS_TPS2;
                break;
        case DP_TRAINING_PATTERN_SEQUENCE_3:
-               ts = DPIA_TS_TPS3;
+               *ts = DPIA_TS_TPS3;
                break;
        case DP_TRAINING_PATTERN_SEQUENCE_4:
-               ts = DPIA_TS_TPS4;
+               *ts = DPIA_TS_TPS4;
                break;
-       default:
-               ts = DPIA_TS_DPRX_DONE;
-               ASSERT(false); /* TPS not supported by helper function. */
+       case DP_TRAINING_PATTERN_VIDEOIDLE:
+               *ts = DPIA_TS_DPRX_DONE;
+               break;
+       default: /* TPS not supported by helper function. */
+               ASSERT(false);
+               *ts = DPIA_TS_DPRX_DONE;
+               status = DC_UNSUPPORTED_VALUE;
                break;
        }
 
-       return ts;
+       return status;
 }
 
 /* Write training pattern to DPCD. */
@@ -336,10 +340,7 @@ static enum link_training_result dpia_training_cr_non_transparent(
                /* DPOA-to-x */
                /* Instruct DPOA to transmit TPS1 then update DPCD. */
                if (retry_count == 0) {
-                       ts = convert_trng_ptn_to_trng_stg(lt_settings->pattern_for_cr);
-                       status = core_link_send_set_config(link,
-                                       DPIA_SET_CFG_SET_TRAINING,
-                                       ts);
+                       status = convert_trng_ptn_to_trng_stg(lt_settings->pattern_for_cr, &ts);
                        if (status != DC_OK) {
                                result = LINK_TRAINING_ABORT;
                                break;
@@ -421,13 +422,14 @@ static enum link_training_result dpia_training_cr_non_transparent(
        if (link->is_hpd_pending)
                result = LINK_TRAINING_ABORT;
 
-       DC_LOG_HW_LINK_TRAINING("%s\n DPIA(%d) clock recovery\n"
-               " -hop(%d)\n - result(%d)\n - retries(%d)\n",
+       DC_LOG_HW_LINK_TRAINING(
+               "%s\n DPIA(%d) clock recovery\n -hop(%d)\n - result(%d)\n - retries(%d)\n - status(%d)\n",
                __func__,
                link->link_id.enum_id - ENUM_ID_1,
                hop,
                result,
-               retry_count);
+               retry_count,
+               status);
 
        return result;
 }
@@ -631,7 +633,11 @@ static enum link_training_result dpia_training_eq_non_transparent(
 
                /* Instruct DPOA to transmit TPSn then update DPCD. */
                if (retries_eq == 0) {
-                       ts = convert_trng_ptn_to_trng_stg(tr_pattern);
+                       status = convert_trng_ptn_to_trng_stg(tr_pattern, &ts);
+                       if (status != DC_OK) {
+                               result = LINK_TRAINING_ABORT;
+                               break;
+                       }
                        status = core_link_send_set_config(link,
                                        DPIA_SET_CFG_SET_TRAINING,
                                        ts);
@@ -712,13 +718,14 @@ static enum link_training_result dpia_training_eq_non_transparent(
        if (link->is_hpd_pending)
                result = LINK_TRAINING_ABORT;
 
-       DC_LOG_HW_LINK_TRAINING("%s\n DPIA(%d) equalization\n"
-               " - hop(%d)\n - result(%d)\n - retries(%d)\n",
+       DC_LOG_HW_LINK_TRAINING(
+               "%s\n DPIA(%d) equalization\n - hop(%d)\n - result(%d)\n - retries(%d)\n - status(%d)\n",
                __func__,
                link->link_id.enum_id - ENUM_ID_1,
                hop,
                result,
-               retries_eq);
+               retries_eq,
+               status);
 
        return result;
 }