drm/amd/display: Check correct bounds for stream encoder instances for DCN303

commit 89b008222c2bf21e50219725caed31590edfd9d1 upstream.

[Why & How]
eng_id for DCN303 cannot be more than 1, since we have only two
instances of stream encoders.

Check the correct boundary condition for engine ID for DCN303 prevent
the potential out of bounds access.

Fixes: cd6d421e3d1a ("drm/amd/display: Initial DC support for Beige Goby")
Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
Cc: stable@vger.kernel.org
Reviewed-by: Chris Park <Chris.Park@amd.com>
Reviewed-by: Rodrigo Siqueira <Rodrigo.Siqueira@amd.com>
Acked-by: Tom Chung <chiahsuan.chung@amd.com>
Signed-off-by: Aurabindo Pillai <aurabindo.pillai@amd.com>
Tested-by: Daniel Wheeler <daniel.wheeler@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/gpu/drm/amd/display/dc/dcn303/dcn303_resource.c b/drivers/gpu/drm/amd/display/dc/dcn303/dcn303_resource.c
index 589ddab61c2a901481fb66e94df0f2d08a40d87a..7aad0340f7946bbce1ea59905648cb338d1273c6 100644 (file)
--- a/drivers/gpu/drm/amd/display/dc/dcn303/dcn303_resource.c
+++ b/drivers/gpu/drm/amd/display/dc/dcn303/dcn303_resource.c
@@ -500,7 +500,7 @@ static struct stream_encoder *dcn303_stream_encoder_create(enum engine_id eng_id
        int afmt_inst;
 
        /* Mapping of VPG, AFMT, DME register blocks to DIO block instance */
-       if (eng_id <= ENGINE_ID_DIGE) {
+       if (eng_id <= ENGINE_ID_DIGB) {
                vpg_inst = eng_id;
                afmt_inst = eng_id;
        } else