drm/amd/display: Avoid overflow assignment in link_dp_cts

sampling_rate is an uint8_t but is assigned an unsigned int, and thus it
can overflow. As a result, sampling_rate is changed to uint32_t.

Similarly, LINK_QUAL_PATTERN_SET has a size of 2 bits, and it should
only be assigned to a value less or equal than 4.

This fixes 2 INTEGER_OVERFLOW issues reported by Coverity.

Signed-off-by: Alex Hung <[email protected]>
Reviewed-by: Wenjing Liu <[email protected]>
Tested-by: Daniel Wheeler <[email protected]>
Signed-off-by: Rodrigo Siqueira <[email protected]>
Signed-off-by: Alex Deucher <[email protected]>

Author: Alex Hung

drivers/gpu/drm/amd/display/dc/dc_dp_types.h

@@ -727,7 +727,7 @@ struct dp_audio_test_data_flags {
 struct dp_audio_test_data {
 
 	struct dp_audio_test_data_flags flags;
-	uint8_t sampling_rate;
+	uint32_t sampling_rate;
 	uint8_t channel_count;
 	uint8_t pattern_type;
 	uint8_t pattern_period[8];

drivers/gpu/drm/amd/display/dc/link/accessories/link_dp_cts.c

@@ -775,7 +775,8 @@ bool dp_set_test_pattern(
 			core_link_read_dpcd(link, DP_TRAINING_PATTERN_SET,
 					    &training_pattern.raw,
 					    sizeof(training_pattern));
-			training_pattern.v1_3.LINK_QUAL_PATTERN_SET = pattern;
+			if (pattern <= PHY_TEST_PATTERN_END_DP11)
+				training_pattern.v1_3.LINK_QUAL_PATTERN_SET = pattern;
 			core_link_write_dpcd(link, DP_TRAINING_PATTERN_SET,
 					     &training_pattern.raw,
 					     sizeof(training_pattern));

drivers/gpu/drm/amd/display/include/dpcd_defs.h

@@ -76,6 +76,7 @@ enum dpcd_phy_test_patterns {
 	PHY_TEST_PATTERN_D10_2,
 	PHY_TEST_PATTERN_SYMBOL_ERROR,
 	PHY_TEST_PATTERN_PRBS7,
+	PHY_TEST_PATTERN_END_DP11 = PHY_TEST_PATTERN_PRBS7,
 	PHY_TEST_PATTERN_80BIT_CUSTOM,/* For DP1.2 only */
 	PHY_TEST_PATTERN_CP2520_1,
 	PHY_TEST_PATTERN_CP2520_2,