drm/amd/display: Skip finding free audio for unknown engine_id

[ Upstream commit 1357b2165d9ad94faa4c4a20d5e2ce29c2ff29c3 ]

[WHY]
ENGINE_ID_UNKNOWN = -1 and can not be used as an array index. Plus, it
also means it is uninitialized and does not need free audio.

[HOW]
Skip and return NULL.

This fixes 2 OVERRUN issues reported by Coverity.

Reviewed-by: Rodrigo Siqueira <rodrigo.siqueira@amd.com>
Acked-by: Wayne Lin <wayne.lin@amd.com>
Signed-off-by: Alex Hung <alex.hung@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>

diff --git a/drivers/gpu/drm/amd/display/dc/core/dc_resource.c b/drivers/gpu/drm/amd/display/dc/core/dc_resource.c
index 8873acfe309c8ce2e5ab2c065c207fa87496e877..84923c5400d32d76ad775b29127c8aabdd8014f2 100644 (file)
--- a/drivers/gpu/drm/amd/display/dc/core/dc_resource.c
+++ b/drivers/gpu/drm/amd/display/dc/core/dc_resource.c
@@ -2385,6 +2385,9 @@ static struct audio *find_first_free_audio(
 {
        int i, available_audio_count;
 
+       if (id == ENGINE_ID_UNKNOWN)
+               return NULL;
+
        available_audio_count = pool->audio_count;
 
        for (i = 0; i < available_audio_count; i++) {