[PATCH 17/39] drm/amd/display: Avoid overflow assignment in link_dp_cts

[Rodrigo Siqueira]

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

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 <alex.hung at amd.com>
Reviewed-by: Wenjing Liu <wenjing.liu at amd.com>
Signed-off-by: Rodrigo Siqueira <rodrigo.siqueira at amd.com>
---
 drivers/gpu/drm/amd/display/dc/dc_dp_types.h                  | 2 +-
 drivers/gpu/drm/amd/display/dc/link/accessories/link_dp_cts.c | 3 ++-
 drivers/gpu/drm/amd/display/include/dpcd_defs.h               | 1 +
 3 files changed, 4 insertions(+), 2 deletions(-)

diff --git a/drivers/gpu/drm/amd/display/dc/dc_dp_types.h b/drivers/gpu/drm/amd/display/dc/dc_dp_types.h
index 519c3df78ee5..95c275bf649b 100644
--- a/drivers/gpu/drm/amd/display/dc/dc_dp_types.h
+++ b/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];
diff --git a/drivers/gpu/drm/amd/display/dc/link/accessories/link_dp_cts.c b/drivers/gpu/drm/amd/display/dc/link/accessories/link_dp_cts.c
index df3781081da7..32d5a4b14333 100644
--- a/drivers/gpu/drm/amd/display/dc/link/accessories/link_dp_cts.c
+++ b/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));
diff --git a/drivers/gpu/drm/amd/display/include/dpcd_defs.h b/drivers/gpu/drm/amd/display/include/dpcd_defs.h
index aee5170f5fb2..c246235e4afe 100644
--- a/drivers/gpu/drm/amd/display/include/dpcd_defs.h
+++ b/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,
-- 
2.43.0